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  • 201.
    Mattsson, C. Mikael
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Björn Ekblom's research group.
    Vad vet vi idag om konditionsträning?2010In: Svensk Idrottsforskning: Organ för Centrum för Idrottsforskning, ISSN 1103-4629, Vol. 19, no 2, p. 10-13Article in journal (Other academic)
    Abstract [sv]

    Finns det några nyheter om konditionsträning? Eller är det samma gamla skåpmat som ompaketeras och tröskas ett nytt varv? Artikeln är ett försök att klargöra en del grundläggande bitar, samt att plocka fram några nya aspekter på området.

  • 202.
    Mattsson, C. Mikael
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's and Mats Börjesson's research group.
    Berglund, Bo
    Department of Medicine, Internal Medicine Unit, Karolinska Institutet, Karolinska University Hospital Solna, Sweden.
    Ekblom, Björn
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's and Mats Börjesson's research group.
    Extreme values of NT-proBNP after ultra-endurance exercise in healthy athletes – Related to impaired exercise performance?2011Article in journal (Refereed)
  • 203.
    Mattsson, C. Mikael
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences.
    Björkman, Frida
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Björn Ekblom's research group.
    Edin, Fredrik
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Björn Ekblom's research group.
    Larsen, Filip
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Björn Ekblom's research group.
    Ekblom, Björn
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Björn Ekblom's research group.
    Regular moist snuff dipping does not affect endurance exercise performance2013Conference paper (Refereed)
    Abstract [en]

    Physiological and medical effects of snuff have previously been obtained either in cross-sectional studies or after snuff administration to non-tobacco users, but the effects of snuff cessation (SC) after several years of daily use on individual level are unknown. 24 participants with >2 years of daily snuff-use were tested before and after >6 weeks SC (SCG), together with a control group (CO) of 11 snuff users who kept their normal habits. Resting heart rate (HR) was significantly lower in SCG after SC. Body mass in SCG group increased by 1.4 ± 1.7 kg and blood pressure (BP) were reduced, but without significant differences between groups. Total cholesterol increased from 4.12 ± 0.54 (95% CI 3.89–4.35) to 4.46 ± 0.70 (95% CI 4.16–4.75) mM/L in SCG, due to increased LDL, and this change was significantly different from CO. Resting values of HDL, C-reactive protein, and free fatty acids (FFA) remained unchanged in both groups. During a four-stage incremental (from 50 to 80% of VO2max) and a prolonged (60 min at 50% of VO2max) cycling test HR and BP were reduced in SCG, while oxygen uptake (VO2), respiratory exchange ratio, blood lactate (bLa) and blood glucose (bGlu) concentration, and rate of perceived exertion were unchanged. All measurements were unchanged in CO. During the prolonged exercise FFA was reduced but there was no significant difference between groups. During the maximal treadmill running test peak values of VO2, pulmonary ventilation (VE), time to exhaustion and bLa were unchanged in both groups. In conclusion, endurance exercise performance (VO2max and maximal endurance time) does not seem to be affected by prolonged snuff use, while effects on cardiovascular risk factors are contradictory.

  • 204.
    Mattsson, C. Mikael
    et al.
    Swedish School of Sport and Health Sciences, GIH.
    Enqvist, Jonas
    Swedish School of Sport and Health Sciences, GIH.
    Brink-Elfegoun, Thibault
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Björn Ekblom's research group.
    Johansson, Patrik
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Björn Ekblom's research group.
    Bakkman, Linda
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Research group for Mitokondriell funktion och metabolisk kontroll.
    Ekblom, Björn
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Björn Ekblom's research group.
    Unexpected cardiovascular response during ultra-endurance exercise.2008In: 13th Annual Congress of the European College of Sport Science (ECSS), Estoril, Lissabon, Portugal.: Sport Science by the sea, 2008, p. 142-Conference paper (Other academic)
    Abstract [en]

    During prolonged exercise at fixed work rate heart rate (HR) increases slowly with concomitant decrease in stroke volume (SV) in order to maintain cardiac output. Simultaneously, an increased oxygen uptake (VO2) occurs. In this paper we report an unexpected and previously not observed cardiovascular response to ultra-endurance exercise. Nine well-trained male athletes performed 24-h exercise in a controlled laboratory setting, with altering blocks of kayaking, running and cycling. Each block consisted of 110 min of exercise and 10 min of rest. Measurements (HR, VO2 and blood samples) were conducted during cycling at fixed work rate every 6th hour. The average work intensity was approximately 55 % of respective VO2peak. HR was increased at 6 h with 15 beats/min (13 %) compared to pre-exercise (Pre-Ex), but thereafter unexpectedly returned towards initial values. VO2 on the other hand was increased with 0.22 l/min (10 %) at 6 h and 0.37 l/min (17 %) at 12 h compared to Pre-Ex, and thereafter remained stable. This implies an increased oxygen pulse (VO2/HR) with approximately 10 % compared to Pre-Ex at the later half of the exercise. The cardiovascular drift did not progress continuously, but instead changed drastically when duration exceeded 6 hours. The changes in HR and VO2 might have different and complex explanations. HR drift might be explained mainly by central circulatory adaptation (e.g. desensitisation of cardiac adrenergic receptors) whereas drift in VO2 may depend upon peripheral changes (e.g. decreased mitochondrial efficiency). Consequently, using solely HR for determining exercise intensity and energy expenditure becomes invalid during ultra-endurance exercise, if the cardiovascular drift is not measured and taken into account.

     

  • 205.
    Mattsson, C. Mikael
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Björn Ekblom's research group.
    Enqvist, Jonas K.
    Inst för kost- och idrottsvetenskap, Göteborgs universitet.
    Stort underskott på energi2011In: Svensk IdrottsMedicin, ISSN 1103-7652, Vol. 30, no 4, p. 12-17Article in journal (Other academic)
    Abstract [sv]

    Det är vanligt att multisportare hamnar i negativ energibalans. Det tycks vara svårt att äta tillräckligt för att täcka det enormt stora energibehovet. Kostrekommendationer för uthållighetsidrottare är heller inte helt gångbara inom multisport.

  • 206.
    Mattsson, C. Mikael
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Björn Ekblom's research group.
    Enqvist, Jonas K.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Björn Ekblom's research group.
    Träning för långdistans: De senaste rönen2007In: Outside, ISSN 1652-4624, no 3, p. 44-48Article in journal (Other academic)
    Abstract [sv]

    Många tidskrifter skriver om optimala metoder för att öka sin prestationsförmåga, gå ner i vikt, eller helt enkelt se snyggare ut. Följande artikel är ett försök att ge dig verktygen för att själv kunna optimera din träning. 

  • 207.
    Mattsson, C. Mikael
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Björn Ekblom's research group.
    Enqvist, Jonas K
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Björn Ekblom's research group.
    Berglund, Bo
    Karolinska Institutet.
    Ekblom, Björn
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Björn Ekblom's research group.
    Extreme values of cardiac peptide NT-proBNP after ultra-endurance exercise in healthy athletes2010In: Book of Abstracts of the 15th Annual Congress of the European College of Sport Science – 23-26 June 2010 Antalya - Turkey.: Sport Science: Where the cultures meet / [ed] Korkusuz, F., Ertan, H., Tsolakidis, E., 2010, p. 35-36Conference paper (Other academic)
    Abstract [en]

    Introduction: In clinical medicine, natriuretic peptides, including N-terminal B-type natriuretic peptide (NT-proBNP), are used to detect increased myocardial wall tension in conditions such as heart failure. Tachycardia, arrhythmias and physical exercise may also increase these peptides. The clinical reference value is <100 ng/l, and in clinical practice values >300 ng/l are a strong indicators of heart failure, and values >5000 ng/l highly significant for mortality within 3 months.

    Methods: We examined the levels of NT-proBNP after ultra-endurance exercise, and also made an attempt to relate NT-proBNP to performance. The subjects (12 males and 3 females) participated in the Adventure Racing World Championship, a 5-6 days non-stop competition open for mixed gender team of four athletes. They were all healthy, well-trained athletes with experience from several years of competitions at international elite level. Blood samples for determination of NT-proBNP were drawn before exercise (Pre-Ex), at the end of the race (End-Ex) and 24 hours after exercise (Post-Ex). Each athlete rated his/her own performance at the end of the race (i.e. the last 12 hours) on a scale from 1 (good, stronger than teammates), 2 (intermediate) and 3 (poor, got towed in, needed help from teammates). In addition, each athlete was also rated according to the same scale by the other three members of his/her team. Thereafter the four rates were pooled. Note that the rating is in relation to the team rather than the result of the competition.

    Results: The average exercise duration was approx. 150 hours, and the calculated average work intensity was 40 % (in percent of respective VO2peak), including time for rest, change of equipment, and food intake. The levels of NT-proBNP increased from 31 ± 14 (10-56) [mean ± SD (min-max)] at Pre-Ex to 487 ± 648 (52-2480) at End-Ex. At Post-Ex the corresponding levels were 224 ± 219 (12-634). At End-Ex seven subjects had NT-proBNP below the reference value. The rated performance for four of them was 1, and the remaining three were rated as 2. Three of the subjects had markedly higher levels than previously reported (>900 ng/l) and they were rated 3, 3 and 2, respectively.

    Discussion: Extreme levels of NT-proBNP, up to 2500 ng/l, are present after ultra-endurance exercise in healthy athletes without any clinical signs or symptoms of heart failure. On the other hand, these extreme values may be an indicator of cardiac fatigue, previously described after endurance exercise. Furthermore, in this study high levels of NT-proBNP seem to be associated with decreased exercise performance.

  • 208.
    Mattsson, C. Mikael
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Björn Ekblom's research group.
    Enqvist, Jonas K
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Björn Ekblom's research group.
    Brink-Elfegoun, Thibault
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Björn Ekblom's research group.
    Johansson, Patrik H
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Björn Ekblom's research group.
    Bakkman, Linda
    Swedish School of Sport and Health Sciences, GIH.
    Ekblom, Björn
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Björn Ekblom's research group.
    Reversed drift in heart rate but increased oxygen uptake at fixed work rate during 24 h ultra-endurance exercise.2010In: Scandinavian Journal of Medicine and Science in Sports, ISSN 0905-7188, E-ISSN 1600-0838, Vol. 20, no 2, p. 298-304Article in journal (Refereed)
    Abstract [en]

    In this paper we report a reversed drift in heart rate (HR) but increased oxygen uptake (VO(2)) during ultra-endurance exercise. Nine well-trained male athletes performed 24-h exercise in a controlled laboratory setting, with alternating blocks of kayaking, running and cycling. Each block included 110 min of exercise and 10 min of rest, with an average work intensity of approximately 55% of respective VO(2peak). Blood samples were taken and HR and VO(2) measured every 6th hour during steady-state cycling at fixed work rate. As assumed HR was increased at 6 h by 15 +/- 6 beats/min compared with initial level (0 h). Thereafter the drift did not progress continuously, but instead unexpectedly returned toward initial values, although the plasma levels of catecholamines increased continuously during exercise. VO(2) was increased by 0.22 +/- 0.15 L/min (10%) at 6 h and 0.37 +/- 0.18 L/min (17%) at 12 h compared with 0 h, and thereafter remained stable. This implies an increased oxygen pulse (VO(2)/HR) by approximately 10% at the last half of the 24-h exercise compared with 0 h. Consequently, sole use of HR would give inaccurate estimates of exercise intensity and energy expenditure during endurance exercise lasting more than 6 h, and different patterns of cardiovascular drift need to be taken into account.

  • 209.
    Mattsson, C. Mikael
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences.
    Enqvist, Jonas K.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Björn Ekblom's research group.
    Ekblom, Björn
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Björn Ekblom's research group.
    The adventure racing athlete: a physiological profile2013Conference paper (Refereed)
    Abstract [en]

    Introduction: The aim of this study was anthropometric and physiological characterisation of male and female adventure racing athletes (ARs), and also to compare top and bottom finishers in the Adventure Racing World Championship (ARWC) 2006.

    Methods: The physiological profile was developed from oxygen uptake during submaximal and maximal exercise on treadmill, cycle- and kayakergometers. The characterisation study included 15 male and 9 female ARs. Additional anthropometric measurements were obtained from 128 participants in the ARWC.

    Results: The anthropometrics for male ARs were: [mean (95% confidence interval)] age 33 (32-34) years, height 180 (179-181) cm, body mass (BM) 79.4 (78.1-80.7) kg, body fat 17.1 (16.5-17.7) % of BM. Corresponding values for female ARs were: age 31 (30-32) years, height 165 (163-167) cm, BM 61.6 (59.8-63.4) kg, body fat 24.7 (23.6-25.8) % of BM. The men's peak oxygen uptakes were: running 5.02 (4.82-5.22), cycling 4.99 (4.80-5.18), and kayaking 4.05 (3.84-4.26) L/min. Corresponding values for the women were: running 3.26 (3.02-3.50), cycling 3.27 (3.05-3.47), and kayaking 2.59 (2.34-2.84) L/min. The characterized ARs had fractional utilisation in the order: running > cycling > kayaking (best trained in running), indicating that a shift in training regime in favour of kayak training could result in better overall performance. Top male finishers in the ARWC were taller, heavier, had a higher BMI and a trend towards higher body fat than bottom finishers, while there were no such differences among the women. The ARs display a distinct profile, in both anthropometric and physiological aspects, which differs from the specialist athletes'. The ARs have to balance a wide variety of demands, such as sufficient endogenous storage of fat and high ability to carry, against sustained ability to run and perform other BM related tasks.

  • 210.
    Mattsson, C. Mikael
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences.
    Flockhart, Mikael
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's research group.
    Söderlund, Karin
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology.
    Hendo, Gina
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology.
    Jakobsson, Madeleine
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology.
    Pontén, Marjan
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology.
    Ekblom, Björn
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's research group.
    Effects of prolonged low intensity exercise with energy deficit (military training operation) on markers of muscle protein turnover.2015Conference paper (Refereed)
    Abstract [en]

    Introduction

    It is well known that ultra-endurance exercise, such as Adventure racing and military operations, often induce substantial energy deficits. This suggests a catabolic state, but the exact effects on protein turnover have not yet been sufficiently investigated. The aim of this study was to examine several markers involved in muscle protein turnover before and after a multi-day physically demanding military training operation.

    Methods

    Seven female (age 21 ± 5 years, weight 71.2 ± 6.6 kg) and seventeen male (age 20 ± 1 years, weight 76.6 ± 6.2 kg) performed a 185 hours military training operation. Energy intake was estimated from food supply and energy expenditure was calculated from continuous heart rate and accelerometer recordings. Muscle biopsies were taken from M Vastus Lateralis before and after the operation.

    Results

    A negative energy balance of 1,500-2,000 kcal/24 hours was estimated. Body weight declined 3.4 (95% CI 3.0-3.8) kg and muscle explosive strength, evaluated from squad and counter movement jumps, was reduced 5 and 6 %, respectively, after the operation with no difference between genders. Muscle glycogen content was reduced from 269 ± 58 to 181 ± 44 mmol/kg dry muscle (p<0.05) with no difference between genders. Muscle content of mTOR and p70 as well as MAFbx were unchanged while the protein content of MuRF-1 was significantly down regulated in both genders.

    Discussion

    The study indicated that prolonged low intensity exercise with substantial energy deficit reduces muscle function and muscle glycogen content. Proteins for muscle synthesis mTOR and p70 were unchanged while the down regulation of MuRF-1 indicates a protection against muscle break down during the energy deficit situation, preserving the muscle mass.

  • 211.
    Mattsson, C. Mikael
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's research group.
    Jansson, Eva
    Karolinska institutet.
    Hagströmer, Maria
    Karolinska institutet.
    Fysisk aktivitet - begrepp och definitioner2016In: FYSS 2017: fysisk aktivitet i sjukdomsprevention och sjukdomsbehandling, Läkartidningen förlag , 2016, p. 21-34Chapter in book (Other academic)
    Abstract [sv]

    Sammanfattning

    Fysisk aktivitet är ett komplext beteende och definieras, rent fysiologiskt, som all kroppsrörelse som ökar energiförbrukningen utöver viloförbrukning.

    Aerob fysisk aktivitet är den vanligaste formen och kan utföras på olika intensiteter, från låg till mycket hög. Aerob fysisk aktivitet som utförs i strukturerad form med syfte att öka eller bibehålla konditionen kan benämnas konditionsträning.

    Muskelstärkande fysisk aktivitet är den form av fysisk aktivitet som belastar och ställer krav på muskelstyrkan. Muskelstärkande fysisk aktivitet som utförs i strukturerad form kan benämnas styrketräning.

    Grundläggande principer för kroppens svar på träning, som ”overload”, progression, reversibilitet, specificitet och individuella skillnader presenteras.

  • 212.
    Mattsson, C. Mikael
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences.
    Larsen, Filip
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's and Mats Börjesson's research group.
    Kondition och uthållighet: För träning, tävling och hälsa2013Book (Other (popular science, discussion, etc.))
    Abstract [sv]

    Vilken intervallform är den mest effektiva i syfte att förbättra konditionen? Är det viktigt att ett träningsupplägg styrs av individualisering? Vilka positiva hälsoeffekter medför en förbättrad kondition? Och vad händer i framtiden – kommer drömgränsen under två timmar på maraton, att sprängas?

    En sammanställning och tolkning av den kunskap vi i nuläget har om fysiologi och träningslära.

    Boken Kondition och uthållighet är en sammanställning och tolkning av den kunskap vi i nuläget har om fysiologi och träningslära. Den beskriver en mängd faktorer och situationer kopplade till träning, prestation, utveckling och hälsa. Den vägleder dig som planerar och genomför träningen - aktiv eller tränare – att välja rätt träningsupplägg med hänsyn till träningsgrad och ambitionsnivå.

    Hälsoeffekter och ofattbara prestationer

    Att träna sin kondition medför en lång rad positiva hälsoeffekter såsom ökad livslängd, förbättrad livskvalitet och minskad risk för en mängd sjukdomar. Vid ökad träningsdos genomgår kroppen en rad förändringar för att anpassa sig till de krav som belastningen kräver. Kroppen är lyckligtvis enormt anpassningsbar och får den bara tillräckligt mycket träning kan den lära sig att tåla stora påfrestningar. Detta bidrar till att idrottare som specialiserar sig, och tränar mycket under lång tid, kan uppnå häpnadsväckande prestationer. Ju sämre kondition och uthållighet du har, desto mindre krävs för att du ska förbättra dig. Ju bättre kondition och uthållighet du har, desto hårdare belastning krävs för att du ska förbättra dig ytterligare.

    Pulsträning

    Ett sätt att mäta träningsbelastning är att använda puls och pulsklocka. Författarna, som även har skrivit träningshäftet Pulsträning (SISU Idrottsböcker 2011), förordar en indelning med sex intensitetszoner som baseras på beräkningar av individuella värden på vilo-, tröskel- och maxpuls. Beroende på hur vältränad man är kommer de olika zonerna att hamna mellan olika pulsnivåer. I den här boken beskrivs vad som tränas i de olika zonerna och varför man utför denna träning, samt hur man ska fördela träningsmängden mellan de olika zonerna.

    Intervallträning och individualisering

    Intervallträning innebär att man delar upp ett träningspass i mindre bitar med viloperioder i mellan, vilket möjliggör att hårda träningspass kan genomföras med en större mängd arbete på hög intensitet. Forskning tyder på att högintensiv intervallträning behövs för att man ska få ut så mycket som möjligt av sin konditionsträning. Vid intervallträning är det extra tydligt att man för bästa effekt bör utgå från sin egen förmåga; att man strävar efter en relativ belastning och upplevelse av trötthet, under och efter intervallpassen.

    Bokens upplägg

    Bokens första del går igenom grunderna i fysiologi och den andra delen handlar om vad som händer och vad man behöver tänka på vid planering, utförande och utvärdering av träning och tävling i konditions- och uthållighetsidrotter. Kondition och uthållighet tar också upp områden som återhämtning, skador, olika riskfaktorer och näringslära, vilka har en direkt betydelse för konditionsträning, oavsett om det handlar om att vinna OS eller träning för hälsa och ett långt aktivt liv.

  • 213.
    Mattsson, C. Mikael
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's and Mats Börjesson's research group.
    Larsen, Filip
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's and Mats Börjesson's research group.
    Pulsträning2011Book (Other (popular science, discussion, etc.))
    Abstract [sv]

    Att träna pulsbaserat skapar perfekta förutsättningarna för en positiv utveckling av din kondition eftersom du tränar utifrån din egen förmåga. Pulsen hjälper dig att träna på rätt nivå på de enskilda träningspassen och kan användas vid all form av konditionsträning. I häftet Pulsträning lär du dig grunderna för att träna med puls och hur du genom att använda olika belastningar kan uppnå olika effekter av din träning.  Du får också förslag på olika tester som både hjälper dig att träna effektivare och skapar motivation.

  • 214.
    Mattsson, C. Mikael
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Björn Ekblom's research group.
    Lind, Britta
    KTH, Skolan för teknik och hälsa.
    Enqvist, Jonas K.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Björn Ekblom's research group.
    Mårtensson, Mattias
    KTH, Skolan för teknik och hälsa.
    Ekblom, Björn
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Björn Ekblom's research group.
    Brodin, Lars-Åke
    KTH, Skolan för teknik och hälsa.
    No evidence of cardiac fatigue in tissue velocity curves at rest after 6 days of ultra-endurance exercise2010In: European Heart Journal (2010) 31 (Abstract Supplement), 304-305, Oxford Journals , 2010, Vol. 31, no Abstract supplement, p. 304-305Conference paper (Refereed)
    Abstract [en]

    Purpose: The aim of this study was to investigate if extreme workload would induce signs of cardiac fatigue similar to that in skeletal muscle, e.g. decreased velocity of contraction.

    Methods: The subjects were 12 men and 3 women who participated in the Adventure Racing World Championship, a 5-7 days non-stop competition open for mixed gender teams of four. All subjects were healthy, well-trained ultra-endurance athletes with experince from several years of training and competition at international elite level. Measurements of the heart's contraction velocities were conducted using tissue Doppler imaging (VIVID7) in a resting situation at baseline, immediately after the race, and after 24 hours of recovery.

    Results: Characteristics for the subjects were at baseline (mean ± SD, for men and women): age 30±3 and 27±4; interventricular septal thickness 10.5±0.7 and 8.0±0.0 mm; left ventricular end-diastolic diameter 54.4±3.4 and 45.0±3.0 mm; posterior wall thickness 10.4±0.9 and 8.0±1.0 mm; early to late diastolic filling velocity (E/A) 2.3±0.6 and 2.2±0.2. Exercise duration was approx. 150 hours, and the calculated average work intensity was 40% of respective VO2peak, including time for rest, change of equipment, and food intake. Values of contraction velocities are presented in the table.

    Conclusions: All athletes had normally sized hearts. Based on contraction velocities we found no evidence of cardiac fatigue after ultra-endurance exercise. A difference compared to studies that found cardiac fatigue in other sports (e.g. marathon, triathlon) is that even though our population exercised for an extreme duration the average intensity was low. This might point towards that exercise intensity, not duration, is the primary source for cardiac fatigue.

  • 215.
    Mattsson, C. Mikael
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's and Mats Börjesson's research group.
    Lind, Britta
    School of Technology and Health, Royal Institute of Technology (KTH).
    Enqvist, Jonas K.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's and Mats Börjesson's research group.
    Mårtensson, Mattias
    School of Technology and Health, Royal Institute of Technology (KTH).
    Ekblom, Björn
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's and Mats Börjesson's research group.
    Brodin, Lars-Åke
    School of Technology and Health, Royal Institute of Technology (KTH).
    No evidence of cardiac fatigue in tissue velocity curves at rest after 6 days of ultra-endurance exercise.2011Article in journal (Refereed)
  • 216.
    Mattsson, C. Mikael
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Björn Ekblom's research group.
    Ståhlberg, Marcus
    Institutionen för Medicin, Enheten för kardiologi, Karolinska Universitetssjukhuset.
    Larsen, Filip
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Björn Ekblom's research group.
    Braunschweig, Frieder
    Institutionen för Medicin, Enheten för kardiologi, Karolinska Universitetssjukhuset.
    Ekblom, Björn
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Björn Ekblom's research group.
    Late cardiovascular drift observable during ultra endurance exercise.2011In: Medicine & Science in Sports & Exercise, ISSN 0195-9131, E-ISSN 1530-0315, Vol. 43, no 7, p. 1162-1168Article in journal (Refereed)
    Abstract [en]

    Introduction: The present study investigates the adaptation of the central circulation to ultraenduranceexercise, including the relative contributions of changes in stroke volume (SV) andarterio-venous oxygen difference (a-v O2 diff) to the increased oxygen pulse (VO2/HR).Methods: We evaluated subjects undergoing 12h of mixed exercise at controlled intensity(n=8) and a 53h Adventure race (n=20). Heart rate (HR), oxygen uptake (VO2), and cardiacoutput determined using non-invasive gas rebreathing (CORB) were measured during cyclingat fixed work rate after 0, 4, 8, 12 hours, and 0, 20, and 53 hours of continuous exercise in the12 and 53 h protocol, respectively.Results and Conclusion: The central circulation changed in several steps in response to ultraenduranceexercise. Compared to initial levels, VO2 was increased at every time-point measured.The increase was attributed to peripheral adaptations, confirmed by a close correlation betweenchange in VO2 and change in a-v O2 diff. The first step of the circulatory response was typical ofnormal (early) cardiovascular drift, with increased HR and concomitantly decreased SV andVO2/HR, occurring over the first 4-6 h. The second step, which continued until approximately 12h, included reversed HR-drift, with normalization of SV and VO2/HR. When exercise continueduntil 50 h late cardiovascular drift was noted, characterized by increased VO2/HR, (indicatingmore efficient energy distribution), decreased peripheral resistance, increased stroke volume, anddecreased work of the heart. Since cardiac output was maintained at all time points we interpretthe changes as physiologically appropriate adaptations to ultra-endurance exercise.

  • 217.
    Mattsson, C. Mikael
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Björn Ekblom's research group.
    Wichardt, Emma
    Idrottsmedicin, Umeå universitet.
    NSAID inom multisport2011In: Svensk IdrottsMedicin, ISSN 1103-7652, Vol. 30, no 4, p. 18-21Article in journal (Other academic)
    Abstract [sv]

    Användning av NSAID är mycket vanligt bland deltagare i längre multisporttävlingar. Ofta i tron att NSAID påskyndar återhämtningen, trots att kunskapen om dess påverkan vid idrott är begränsad. Det är till och med möjligt att NSAID har motsatt effekt och istället påverkar muskelåterhämtning och -uppbyggnad negativt.

  • 218. Metaxas, Thomas I
    et al.
    Mandroukas, Athanasios
    Vamvakoudis, Efstratios
    Kotoglou, Kostas
    Ekblom, Björn
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's and Mats Börjesson's research group.
    Mandroukas, Konstantinos
    Muscle fiber characteristics, satellite cells and soccer performance in young athletes.2014In: Journal of Sports Science and Medicine (JSSM), ISSN 1303-2968, Vol. 13, no 3, p. 493-501Article in journal (Refereed)
    Abstract [en]

    This study is aimed to examine the muscle fiber type, composition and satellite cells in young male soccer players and to correlate them to cardiorespiratory indices and muscle strength. The participants formed three Groups: Group A (n = 13), 11.2 ± 0.4yrs, Group B (n=10), 13.1 ± 0.5yrs and Group C (n = 9), 15.2 ± 0.6yrs. Muscle biopsies were obtained from the vastus lateralis. Peak torque values of the quadriceps and hamstrings were recorded and VO2max was measured on the treadmill. Group C had lower type I percentage distribution compared to A by 21.3% (p < 0.01), while the type IIA relative percentage was higher by 18.1% and 18.4% than in Groups A and B (p < 0.05). Groups B and C had higher cross-sectional area (CSA) values in all fiber types than in Group A (0.05 < p < 0.001). The number of satellite cells did not differ between the groups. Groups B and C had higher peak torque at all angular velocities and absolute VO2max in terms of ml·min(-1) than Group A (0.05 < p < 0.001). It is concluded that the increased percentage of type IIA muscle fibers noticed in Group C in comparison to the Groups A and B should be mainly attributed to the different workload exercise and training programs. The alteration of myosin heavy chain (MHC) isoforms composition even in children is an important mechanism for skeletal muscle characteristics. Finally, CSA, isokinetic muscle strength and VO2max values seems to be expressed according to age. Key PointsFifteen years old soccer players have higher IIA percentage distribution than the younger players by approximately 18%.The age and the training status play a crucial role in muscle fibers co-expression.Specific training in young athletes seems to alter significantly the muscular metabolic profile.

  • 219. Mijwel, Sara
    et al.
    Cardinale, Daniele
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Research group for Mitokondriell funktion och metabolisk kontroll.
    Ekblom-Bak, Elin
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's research group.
    Sundberg, Carl Johan
    Wengström, Yvonne
    Rundqvist, Helene
    Validation of 2 Submaximal Cardiorespiratory Fitness Tests in Patients With Breast Cancer Undergoing Chemotherapy.2016In: Rehabilitation oncology (American Physical Therapy Association. Oncology Section), ISSN 2168-3808, Vol. 34, no 4, p. 137-143Article in journal (Refereed)
    Abstract [en]

    Patients with breast cancer have an impaired cardiorespiratory fitness, in part, due to the toxic effects of anticancer therapy. Physical exercise as a means of rehabilitation for patients with cancer is an emerging area of research and treatment, emphasizing the need for accurate and feasible physical capacity measurements. The purpose of this study was to evaluate the validity of peak oxygen consumption (o2peak) predicted by the Ekblom-Bak test (E-B) and the Åstrand-Rhyming prediction model (A-R).

    METHODS: Eight patients with breast cancer undergoing chemotherapy participated in the study. Submaximal exercise tests were performed at 2 different submaximal workloads. Estimated o2peak values were obtained by inserting the heart rate (HR) from the 2 workloads into the E-B prediction model and the HR of only the higher workload into the Åstrand nomogram. A 20-W incremental cycle test-to-peak effort was performed to obtain o2peak values.

    RESULTS: Results from A-R overestimated o2peak by 6% (coefficient of variation = 7%), whereas results from E-B overestimated o2peak with 42% (coefficient of variation = 21%) compared with measured o2peak. Pearson's correlation coefficient revealed a significant strong relationship between the estimated o2peak from A-R and the measured o2peak (r = 0.86; P < .05), whereas the relationship between the estimated o2peak from E-B and the measured o2peak resulted in a nonsignificant weak correlation (r = 0.21).

    CONCLUSION: In a situation where maximal exercise testing is not practical or undesirable from a patient safety perspective, submaximal exercise testing provides an alternative way of estimating o2peak. The A-R prediction model appears to be a valid submaximal exercise test for determining cardiorespiratory fitness in this population.

  • 220.
    Millischer, Vincent
    et al.
    Karolinska institutet.
    Erhardt, Sophie
    Karolinska institutet.
    Ekblom, Örjan
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's research group.
    Forsell, Yvonne
    Karolinska institutet.
    Lavebratt, Catharina
    Karolinska institutet.
    Twelve-week physical exercise does not have a long-lasting effect on kynurenines in plasma of depressed patients2017In: Neuropsychiatric Disease and Treatment, ISSN 1176-6328, E-ISSN 1178-2021, Vol. 13, p. 967-972Article in journal (Refereed)
    Abstract [en]

    Background: Physical exercise has well-characterized positive effects on depressive symptoms. The underlying biologic mechanisms are, however, far from established. A recently discovered mechanism has linked the enhanced conversion of kynurenine to kynurenic acid (KYNA) to an increased resilience toward stress-induced depression in mice. The aim of this study was to translate these findings to humans.

    Materials and methods: Kynurenine and KYNA levels were measured by high-performance liquid chromatography in plasma samples from 117 patients affected by mild-to-moderate depression before and within a week after a 12-week training period at three different intensities. The patients were part of the Regassa study.

    Results: No differences in plasma levels of kynurenine and KYNA or in their ratio could be detected between before and after training. No effect of the intensity group could be observed. No correlation with the improvement in cardiovascular fitness (Åstrand score) or the improvement in mood (Montgomery Åsberg Depression Rating Scale score) could be observed.

    Limitations: As the Regassa study is based on an intention-to-treat protocol, the exact time and the exact intensity of the physical exercise are not known. Analyses of pulse data as well as personal interviews, however, were used to control the exercise protocols. Furthermore, the observations reflect chronic changes.

    Conclusion: Physical exercise positively affects mood and cardiovascular fitness, but does not lead to long-lasting changes in plasma levels of kynurenine and KYNA in patients affected by mild-to-moderate depression.

  • 221.
    Moberg, Marcus
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Eva Blomstrand's research group.
    Apró, William
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Eva Blomstrand's research group.
    Ekblom, Björn
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's and Mats Börjesson's research group.
    Blomstrand, Eva
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Eva Blomstrand's research group.
    High-intensity cycling performed prior to resistance exercise does not influence mTORC1-signaling and the rate of muscle protein synthesis in the triceps brachii2014Conference paper (Other academic)
    Abstract [en]

    Introduction

    Endurance exercise can influence strength training adaptations when performed concurrently, with both inhibition (Kreamer 1995) and augmentation (Lundberg 2012) of muscular hypertrophy being reported. Our lab has set out to conduct a series of studies to examine the influence of endurance exercise on the acute stimulatory effect of resistance exercise on anabolic processes. In the present study, the effect of endurance exercise on a previously inactive muscle was investigated. The aim was to examine the influence of resistance exercise on mTORC1-signaling and rate of protein synthesis in the triceps brachii muscle with or without preceding intervals of high-intensity cycling. 

     

    Methods

    Eight trained males performed, in a randomized fashion, two sessions of heavy resistance exercise (RE) with the triceps muscles, where one session was preceded by intervals of high-intensity cycling (E+RE), 5 x 4 min at 85% of VO2 peak. Mixed muscle protein fractional synthetic rate (FSR) was measured at rest, prior to exercise, and during a 3 hour recovery period following exercise by continuous infusion of L-[ring-13C6] phenylalanine. Muscle biopsies from the triceps brachii was collected twice at rest separated by three hours, directly after resistance exercise and following 90 and 180 min of recovery. Signalling in the mTORC1-and AMPK-pathway was assessed using western blot technique.

     

    Results

    The same amount of work with regard to load, total number of repetitions and total time under tension was performed in the two trials. Muscle protein FSR increased from 0.050 ± 0.006 %/h at rest to 0.078 ± 0.008 and 0.082 ± 0.0016 %/h following E+RE and RE, respectively, with no difference between trials. Phosphorylation (P) of AMPKT172 was increased by 45-65% directly after exercise, similarly in both conditions, and regressed to a level approx. 20% lower than baseline following 180 min of recovery. P-mTORS2448 was increased 76 and 108% above rest directly after the E+RE and RE, respectively, and remained elevated in both trials during the entire recovery period. P-eEF2T56 was 20-36% higher directly after exercise but fell to a level that was 30-36% lower than pre-exercise and remained reduced during the entire recovery, with no difference between trials.

     

    Conclusion

    High-intensity endurance cycling does not influence the acute stimulation of anabolic signalling and muscle protein synthesis in the triceps brachii following resistance exercise.

     

     

    References

    Kreamer WJ et al. (1995) J Appl Physiol 78(3):976-989

    Lundberg T et al. (2013) J Appl Physiol 114: 81-89

  • 222.
    Moberg, Marcus
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Eva Blomstrand's research group.
    Apró, William
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Eva Blomstrand's research group.
    Ekblom, Björn
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's research group.
    Gerrit, van Hall
    Holmberg, Hans-Christer
    Blomstrand, Eva
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Eva Blomstrand's research group.
    Activation of mTORC1 by leucine is potentiated by branched chain amino acids and even more so by essential amino acids following resistance exercise2016In: American Journal of Physiology - Cell Physiology, ISSN 0363-6143, E-ISSN 1522-1563, Vol. 310, no 11, p. C874-C884Article in journal (Refereed)
    Abstract [en]

    Protein synthesis is stimulated by resistance exercise and intake of amino acids, in particular leucine. Moreover, activation of mTORC1 signaling by leucine is potentiated by the presence of other essential amino acids (EAA). However, the contribution of the branched-chain amino acids (BCAA) to this effect is yet unknown. Here we compare the stimulatory role of leucine, BCAA and EAA ingestion on anabolic signaling following exercise. Accordingly, eight trained volunteers completed four sessions of resistance exercise during which they ingested either placebo, leucine, BCAA or EAA (including the BCAA) in random order. Muscle biopsies were taken at rest, immediately after exercise and following 90 and 180 min of recovery. Following 90 min of recovery the activity of S6K1 was greater than at rest in all four trials (Placebo<Leucine<BCAA<EAA; P<0.05 time x supplement), with a 9-fold increase in the EAA trial. At this same time-point phosphorylation of 4E-BP1 at Thr37/46 was unaffected by supplementation, while that of Thr46 alone exhibited a pattern similar to that of S6K1, being 18% higher with EAA than BCAA. However, after 180 min of recovery this difference between EAA and BCAA had disappeared, although with both these supplements the increases were still higher than with leucine (40%, P<0.05) and placebo (100%, P<0.05). In summary, EAA ingestion appears to stimulate translation initiation more effectively than the other supplements, although the results also suggest that this effect is primarily attributable to the BCAA.

  • 223.
    Moberg, Marcus
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Eva Blomstrand's research group.
    Apró, William
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Eva Blomstrand's research group.
    Ohlsson, Inger
    Pontén, Marjan
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences.
    Villanueva, Antonio
    Ekblom, Björn
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's and Mats Börjesson's research group.
    Blomstrand, Eva
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Eva Blomstrand's research group.
    Absence of leucine in an essential amino acid supplement reduces activation of mTORC1 signalling following resistance exercise in young females.2014In: Applied Physiology, Nutrition and Metabolism, ISSN 1715-5312, E-ISSN 1715-5320, Vol. 39, no 2, p. 183-94Article in journal (Refereed)
    Abstract [en]

    The purpose of the study was to investigate the specific effect of leucine on mTORC1 signalling and amino acid metabolism in connection with resistance exercise. Comparisons were made between ingestion of supplements with and without leucine. Eight young women performed leg press exercise on 2 occasions. In randomized order they received either an aqueous solution of essential amino acids with leucine (EAA) or without leucine (EAA-Leu), given as small boluses throughout the experiment. Muscle biopsies were taken after an overnight fast before exercise and 1 and 3 h postexercise and samples of blood were taken repeatedly during the experiment. Plasma and muscle concentrations of leucine rose 60%-140% (p < 0.05) with EAA and fell 35%-45% (p < 0.05) with the EAA-Leu supplement. In the EAA-trial, plasma and muscle levels of tyrosine (not present in the supplement) and the sum of the EAA were 15%-25% (p < 0.05) lower during recovery. Phosphorylation of mTOR and p70S6k was elevated to a larger extent following 1 h of recovery with leucine in the supplement (120% vs. 49% (p < 0.05) and 59- vs. 8-fold (p < 0.05) for EAA and EAA-Leu, respectively). The levels of MAFbx and MuRF-1 mRNA and of the corresponding proteins were not significantly altered after 3 h recovery from exercise. In conclusion, the presence of leucine in the supplement enhances the stimulatory effect on mTORC1 signalling and reduces the level of tyrosine and the sum of the EAA in muscle and plasma, suggesting a stimulation of protein synthesis and (or) inhibition of breakdown, leading to improvement in net protein balance.

  • 224.
    Moberg, Marcus
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Eva Blomstrand's research group.
    Hendo, Gina
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology.
    Jakobsson, Madeleine
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology.
    Mattsson, C. Mikael
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences.
    Ekblom Bak, Elin
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's research group.
    Flockhart, Mikael
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology.
    Pontén, Marjan
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology.
    Söderlund, Karin
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology.
    Ekblom, Björn
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's research group.
    Increased autophagy signalling but not proteasome activity in human skeletal muscle after prolonged low-intensity exercise with negative energy balance2017In: ICSPP Abstracts: Journal of Science and Medicine in Sport, Volume 20, Supplement 2, November 2017, Pages S166, 2017, Vol. 20, no Supplement 2, p. S166-, article id 287Conference paper (Other academic)
  • 225.
    Moberg, Marcus
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's research group.
    Hendo, Gina
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences.
    Jakobsson, Madelene
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences.
    Mattsson, C Mikael
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology.
    Ekblom-Bak, Elin
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology.
    Flockhart, Mikael
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Research group for Mitokondriell funktion och metabolisk kontroll.
    Pontén, Marjan
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology.
    Söderlund, Karin
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology.
    Ekblom, Björn
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's research group.
    Increased autophagy signaling but not proteasome activity in human skeletal muscle after prolonged low-intensity exercise with negative energy balance2017In: Physiological Reports, E-ISSN 2051-817X, Vol. 5, no 23, article id e13518Article in journal (Refereed)
    Abstract [en]

    Little is known about the molecular regulation of skeletal muscle protein turnover during exercise in field conditions where energy is intake inadequate. Here, 17 male and 7 female soldiers performed an 8 day long field based military operation. Vastus lateralis muscle biopsies, in which autophagy, the ubiquitin-proteasome system and the mTORC1 signaling pathway where studied, were collected before and after the operation. The 187 h long operation resulted in a 15% and 29% negative energy balance as well as a 4.1% and 4.6% loss of body mass in women and men respectively. After the operation protein levels of ULK1 as well as the phosphorylation of ULK1Ser317 and ULK1Ser555 had increased by 11%, 39% and 13%, respectively, and this was supported by a 17% increased phosphorylation of AMPKThr172 (P<0.05). The LC3b-I/II ratio was 3-fold higher after compared to before the operation (P<0.05), whereas protein levels of p62/SQSTM1 were unchanged. The β1, β2, and β5 activity of the proteasome and protein levels of MAFbx did not change, while levels of MuRF-1 were slightly reduced (6%, P<0.05). Protein levels and phosphorylation status of key components in the mTORC1 signaling pathway remained at basal levels after the operation. Muscle levels of glycogen decreased from 269±12 to 181±9 mmol ∙ kg dry muscle-1 after the exercise period (P<0.05). In conclusion, the 8 days of field based exercise resulted in induction of autophagy without any increase in proteasome activity or protein ubiquitination. Simultaneously, the regulation of protein synthesis through the mTORC1 signaling pathway was maintained.

  • 226. Nilsson, Hanna
    et al.
    Angerås, Ulf
    Bock, David
    Börjesson, Mats
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's and Mats Börjesson's research group.
    Onerup, Aron
    Fagevik Olsen, Monika
    Gellerstedt, Martin
    Haglind, Eva
    Angenete, Eva
    Is preoperative physical activity related to post-surgery recovery? A cohort study of patients with breast cancer.2016In: BMJ Open, ISSN 2044-6055, E-ISSN 2044-6055, Vol. 6, no 1, article id e007997Article in journal (Refereed)
    Abstract [en]

    OBJECTIVE: The aim of our study is to assess the association between preoperative level of activity and recovery after breast cancer surgery measured as hospital stay, length of sick leave and self-assessed physical and mental recovery.

    DESIGN: A prospective cohort study.

    SETTING: Patients included were those scheduled to undergo breast cancer surgery, between February and November 2013, at two participating hospitals in the Western Region of Sweden.

    PARTICIPANTS: Patients planned for breast cancer surgery filled out a questionnaire before, as well as at 3 and 6 weeks after the operation. The preoperative level of activity was self-assessed and categorised into four categories by the participants using the 4-level Saltin-Grimby Physical Activity Level Scale (SGPALS).

    MAIN OUTCOME MEASURE: Our main outcome was postoperative recovery measured as length of sick leave, in-hospital stay and self-assessed physical and mental recovery.

    RESULTS: 220 patients were included. Preoperatively, 14% (31/220) of participants assessed themselves to be physically inactive, 61% (135/220) to exert some light physical activity (PA) and 20% (43/220) to be more active (level 3+4). Patients operated with mastectomy versus partial mastectomy and axillary lymph node dissection versus sentinel node biopsy were less likely to have a short hospital stay, relative risk (RR) 0.88 (0.78 to 1.00) and 0.82 (0.70 to 0.96). More active participants (level 3 or 4) had an 85% increased chance of feeling physically recovered at 3 weeks after the operation, RR 1.85 (1.20 to 2.85). No difference was seen after 6 weeks.

    CONCLUSIONS: The above study shows that a higher preoperative level of PA is associated with a faster physical recovery as reported by the patients 3 weeks post breast cancer surgery. After 6 weeks, most patients felt physically recovered, diminishing the association above. No difference was seen in length of sick leave or self-assessed mental recovery between inactive or more active patients.

  • 227.
    Nyberg, Gisela
    et al.
    Karolinska institutet.
    Ekblom, Örjan
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Björn Ekblom's research group.
    Stillasittande hos barn och ungdomar2013In: Långvarigt stillasittande: en hälsofara i tiden / [ed] Elin Ekblom Bak, Studentlitteratur, 2013, p. 57-78Chapter in book (Other academic)
  • 228. Nyberg, Gisela
    et al.
    Ekblom, Örjan
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's and Mats Börjesson's research group.
    Marcus, Claude
    A 4-Year Cluster-Randomised Controlled Intervention Study on Physical Activity Pattern and Sedentary Behaviour in Children2011In: Medicine and Science in Sport and Exercise, 2011, Vol. 43, suppl 15, p. 24-24Conference paper (Refereed)
    Abstract [en]

    PURPOSE: The purpose of the present study was to examine the effects of a cluster-randomised, controlled school-based intervention (the STOPP-study) on objectively measured sedentary time, time spent in light intensity activity and in moderate to vigorous physical activity (MVPA).

    METHODS: A total of 1538 children in grades 1-4 from ten selected schools in Stockholm county area were included. Schools were randomised as intervention (n=5) or control (n=5). Physical activity was aimed to increase by 30 min -1day during school time and sedentary behavior was restricted during after school care time. Physical activity was measured by accelerometry. Percentage of time spent sedentary (below 1.5 METs), in light (between 1.5 and 3 METs), and in MVPA (above 3 METs) were primary outcome variables.

    RESULTS: Adjusted for age, gender and calendar year, children in intervention schools spent less time sedentary, compared to children in control schools (32.3% vs. 33.4% of registered time, P=0.03) and more time in MVPA (28.5% vs. 27.6%, P=0.05). Children in the intervention group spent more time in MVPA (37.2% vs. 34.9%, P=0.002) and less time sedentary (22.0% vs. 24.3%, P<0.001) during after school care time. Normal weight and overweight children in intervention schools spent more time in MVPA and less time sedentary during after school care time compared to children in the control schools. Overweight children in the intervention group spent more time in light intensity activity during evening time. There was a trend for less sedentary activities in overweight intervention children during evening time. The results were attenuated after adjustment for the sampling variation between schools.

    CONCLUSIONS: There were indications of differences between intervention and control groups in time spent sedentary and in MVPA among normal weight and overweight children. Although differences were not statistically significant after adjustment for the cluster effect, the present paper provides argument for school-based interventions in order to decrease sedentary behaviour and increase physical activity.

  • 229.
    Oddsson, Kristjan
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, The Laboratory of Applied Sports Science (LTIV).
    Danielsson, Evelina
    Ekblom, Örjan
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Björn Ekblom's research group.
    Nilsson, Johnny
    Swedish School of Sport and Health Sciences, GIH. Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, The Laboratory of Applied Sports Science (LTIV).
    Wahlgren, Lina
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, The Laboratory of Applied Sports Science (LTIV).
    Andersson, Eva
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, The Laboratory of Applied Sports Science (LTIV).
    Development of physical tests and ratings scales of perceived health in a project with supervised physical activity for elderly.2010Conference paper (Refereed)
    Abstract [en]

    Background: Valid and reliable field tests for measuring physical fitness and different health parameters is an important matter for evaluating effects of exercise interventions.

    Purpose: The aim was to study different test parameters such as aerobic capacity, strength, perceived health and life style habits, such as physical activity, in a physical activity intervention for elderly people.

    Method: 117 old-age pensioners (99 women and 18 men). Their mean age (yrs) and BMI (kg/m2 ) was 74 and 26 for the women and 73 and 25 for the men, respectively. Different aerobic, strength and balance tests were measured. Guided physical activity (nordic walking, strength training, aqua gymnastics), were given 45-60 min, 2 times/week for 8-12 weeks. Perceived exertion ratings during the exercises were moderate and/or strong.

    Results: Significant changes (p< 0,05) were seen between pre- and post tests regarding all physical tests except the balance test for men. Even the perceived physical and mental health significantly improved. The mean values for questions concerning self reported inactive/active life style, including sedentary time, were changed to a more active life style.

    Conclusion: 8-12 weeks of guided physical activity can improve several physiological parameters which are positively correlated to decreased risk of numerous diseases. More research is needed to develop reliable and valid field tests for physical capacity and different health parameters.

  • 230.
    Olsson, Gustav
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's and Mats Börjesson's research group.
    Ekblom Bak, Elin
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology.
    Ekblom, Björn
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology.
    Kallings, Lena
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology.
    Ekblom, Örjan
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology.
    Börjesson, Mats
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology. Göteborgs Universitet.
    Is the relationship between self-perceived physical health and measured physical fitness robust over time and between genders?Manuscript (preprint) (Other academic)
  • 231.
    Olsson, Sven Johan Gustav
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's research group.
    Baksidan av myntet - inaktiviteten: Ny avhandling: Studies of physical activity in the Swedish population2016In: Idrottsmedicin, ISSN 2001-3302, Vol. 35, no 3, p. 27-29Article in journal (Other (popular science, discussion, etc.))
    Abstract [sv]

    Sammanfattning av Olssons avhandling

  • 232.
    Olsson, Sven Johan Gustav
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's and Mats Börjesson's research group.
    Studies of physical activity in the Swedish population2016Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Background: Cheap and effective tools for measuring patients’ physical activity (PA) level are needed. The first aim in this thesis was therefore to assess the validity of two PA -questions, and their three associated answer modes, that are used within the Swedish health care system. Sitting, light intensity PA (LIPA), and moderate and vigorous intensity PA (MVPA), are associated with health and longevity, but detailed population data assessed with objective methods is needed. The second aim was thus to assess the above with motion sensor technology, in a middle-aged Swedish sample. Low self-perceived health is a strong predictor of morbidity and mortality, but this association may vary over time with changes in the society and our lifestyle. The third aim was to assess secular trends in the interrelations between self-perceived health, physical fitness, and selected covariates. The effects of PA on prescription (PAP) on health-related quality of life (HRQoL) in overweight adults are unclear, thus the fourth aim was to explore this.

    Methods: All data was collected in the Swedish population. Data from the PA -questions and accelerometers, aerobic fitness, counter movement jump, and balance tests, blood samples, and self-rated general health were collected in 365 participants, 21–66 yrs. The PA pattern was assessed in 948 individuals, 50‒64 yrs, from the SCAPIS pilot study. Self-perceived physical health, and measured aerobic fitness, counter movement jump height, and balance, and demographic and lifestyle data, was assessed in three independent samples from 1990, 2000 and 2013, including 3564 adults, 20‒65 yrs. The effects of Swedish PAP on HRQoL was assessed in a randomized controlled trial including 101 men and women, 67‒68 yrs, that were inactive, overweight (BMI>25 kg/m2), and had a waist circumference ≥102 cm (men) or ≥88 cm (women), who were randomized to an intervention group or a control group. The 36-item Short Form Health Survey (SF-36) was used to assess HRQoL.

    Results: The multiple choice answer mode of the two PA -questions was found to have the strongest validity, compared with the two other (an open mode, and one where PA minutes is specified per weekday). The validity is in line with many other established PA-questionnaires, but the open mode has limitations. The assessment of PA pattern showed that 61% of motion sensor wear time represented sitting, 35% LIPA, and 4% MVPA. Only 7% of the sample met the PA recommendations. The odds for describing perceived health as good was found to increase by 5% per each increment of 1 ml/kg/min in VO2max. This was stable across genders and all three LIV-samples (i.e. over time). Waist circumference, chronic disease, sleep problems, and level of satisfaction with one’s life, were also important correlates. The Swedish PAP group improved significantly more, and more participants displayed clinically relevant improvements (OR 2.43), in mental aspects of HRQoL, compared to the controls. Physical aspects of HRQoL improved in the PAP group, but not in the control group.

    Conclusions: The multiple choice answer mode has the strongest validity and Open mode the weakest. The PA -questions may be used in populations, or in individuals to determine appropriateness for treatment. The questions’ advantages and limitations must be considered and further reliability and validity studies are needed. The results regarding sitting, LIPA, MVPA and fulfillment of PA recommendations, are of high clinical relevance. A great challenge remains to further implement methods to increase the level of PA in the Swedish population. Physical fitness is related to self-perceived health independently of changes in society and lifestyle over time, and simple questions may be useful for the clinical assessment of physical fitness. Swedish PAP has a positive effect on mental aspects of HRQoL, measured by the SF-36. This finding supports the clinical use of the Swedish PAP model.

  • 233.
    Olsson, Sven Johan Gustav
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's research group.
    Börjesson, Mats
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's research group.
    Ekblom Bak, Elin
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's research group.
    Hemmingsson, Erik
    Karolinska Institutet.
    Hellénius, Mai-Lis
    Karolinska Institutet.
    Kallings, Lena
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's research group.
    Effects of the Swedish physical activity on prescription model on health-related quality of life in overweight older adults: a randomised controlled trial2015In: BMC Public Health, ISSN 1471-2458, E-ISSN 1471-2458, Vol. 15, article id 687Article in journal (Refereed)
    Abstract [en]

    Background

    The effects of physical activity on prescription (PAP) on health-related quality of life (HRQoL) in overweight adults are unclear. We therefore aimed to explore the effects of the Swedish PAP model on HRQoL in overweight older adults.

    Methods

    Participants were recruited from a cohort of men and women born between 1937 and 1938, and living in Stockholm County. Inclusion criteria were; insufficiently physically active, i.e. <30 min of at least moderate intensity physical activity (PA) per day; body mass index >25 kg/m 2 ; and waist circumference ≥102 cm (men) or ≥88 cm (women). Altogether, 101 individuals, aged 67 years, were randomly assigned to two parallel groups: intervention group (n = 47) receiving individualised PAP or control group (n = 54). The 36-item Short Form Health Survey (SF-36) was administered before and after the six months intervention. Main outcomes were the SF-36 physical component summary (PCS) and mental component summary (MCS) scores. Intention to treat analysis was utilised. Regression analysis was performed to assess whether changes in PA and body weight affected changes in HRQoL.

    Results

    At the six months follow-up, regarding the MCS score, the intervention group had improved significantly more (median: 4.4 [interquartile range (IQR): −2.4 to 23.3]) vs (median: 0.0 [IQR: −4.0 to 4.9]); p < 0.05) and a higher proportion of participants had attained relevant improvements (OR 2.43 (95 % CI 1.00–5.88) p < 0.05) compared to the controls. A within group improvement in the PCS score (median: 3.8 [IQR: −1.9 to 19.5] p < 0.05) was found in the intervention group. Changes in PA and body weight had a small, but significant, mediating effect on the changes in HRQoL.

    Conclusions

    PAP had a positive effect on HRQoL, measured by the SF-36 MCS, but no significant between group effect was seen on the PCS in overweight older adults. These effects were, to some extent, mediated by changes in PA and body weight. Our findings support clinical use of the Swedish PAP model.

    Trial registration

    ClinicalTrials.gov NCT02320760.

  • 234.
    Olsson, Sven Johan Gustav
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's and Mats Börjesson's research group.
    Ekblom, Örjan
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's and Mats Börjesson's research group.
    Andersson, Eva
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences.
    Börjesson, Mats
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's and Mats Börjesson's research group. Department of Medicine, Unit of Cardiology, Karolinska University Hospital, Solna.
    Kallings, Lena
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's and Mats Börjesson's research group.
    Categorical answer modes provides superior validity to open answers when asking for level of physical activity: A cross-sectional study2016In: Scandinavian Journal of Public Health, ISSN 1403-4948, E-ISSN 1651-1905, Vol. 44, no 1, p. 70-76, article id 1403494815602830Article in journal (Refereed)
    Abstract [en]

    AIMS:

    Physical activity (PA) used as prevention and treatment of disease has created a need for effective tools for measuring patients' PA level. Our aim was therefore to assess the validity of two PA questions and their three associated answer modes.

    METHODS:

    Data on PA according to the PA questions and Actigraph GT3X+ accelerometers, aerobic fitness (VO2max), cardiovascular biomarkers, and self-rated general health were collected in 365 Swedish adults (21-66 years). The PA questions ask about weekly PA via categories (Categorical), an open-ended answer (Open), or specified day by day (Table).

    RESULTS:

    The Categorical mode, compared with the Open mode, correlated (Spearman's rho) significantly more strongly (p<0.05) with accelerometer PA (0.31 vs. 0.18) and VO2max (0.27 vs. 0.06), and the level of BMI (-0.20 vs. -0.02), waist circumference (-0.22 vs. -0.03), diastolic blood pressure (-0.16 vs. 0.08), glucose (-0.18 vs. 0.04), triglycerides (-0.31 vs. -0.07), and general health (0.35 vs. 0.19). The validity of the Categorical and Table modes were similar regarding VO2max and accelerometry, but the Categorical mode exhibited more significant and stronger correlations with cardiovascular biomarkers. The capacity of the PA questions to identify insufficiently physically active individuals ranged from 0.57 to 0.76 for sensitivity and from 0.47 to 0.79 for specificity.

    CONCLUSIONS:

    The Categorical mode exhibits the strongest validity and Open mode the weakest. The PA questions may be used on a population level, or as a tool for determining patents' appropriateness for treatment.

  • 235.
    Olsson, Sven Johan Gustav
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's research group.
    Ekblom-Bak, Elin
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's research group.
    Ekblom, Björn
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's research group.
    Kallings, Lena V
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's research group.
    Ekblom, Örjan
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's research group.
    Börjesson, Mats
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology. Göteborg University.
    Association of perceived physical health and physical fitness in two Swedish national samples from 1990 and 2015.2018In: Scandinavian Journal of Medicine and Science in Sports, ISSN 0905-7188, E-ISSN 1600-0838, Vol. 28, no 2, p. 717-724Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: Perceived health and physical fitness have been shown to correlate, and low levels of either variable increase the risk for future illness and mortality. However, risk factors and their interrelationship may vary between societies and over time. In this study, the associations of physical fitness and perceived health were therefore assessed in two Swedish national samples 25 years apart.

    METHODS: Perceived physical health, dichotomized as "good" or "bad", maximal oxygen uptake (VO2 max), counter movement jump (CMJ), balance (one-legged 60 second stance), and self-reported demographics and lifestyle were recorded in two cross-sectional samples (sample size, number of eligible participants) of Swedish adults, aged 20 - 65 years, in 1990 - 1991 (2203, 1365), and 2013 - 2015 (3357, 422).

    RESULTS: The odds for good perceived physical health increased by 5% per mL · kg(-1) · min(-1) of VO2 max, 3% per cm CMJ height, and decreased by 4% per 1 time of overbalancing, in both samples. Mutually adjusted regression models showed that perceived physical health was best predicted by VO2 max and chronic illness in 1990 and by age, BMI, and educational level in 2015.

    CONCLUSION: Perceived physical health was related to physical fitness in two samples of Swedish adults from 1990 and 2015. However, multivariate, and mutually adjusted models, indicate that the most important covariates of perceived physical health may have changed from VO2 max and chronic illness in 1990, to age, BMI, and educational level in 2015. This article is protected by copyright. All rights reserved.

  • 236. Onerup, Aron
    et al.
    Angerås, Ulf
    Bock, David
    Börjesson, Mats
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's and Mats Börjesson's research group.
    Fagevik Olsén, Monika
    Gellerstedt, Martin
    Haglind, Eva
    Nilsson, Hanna
    Angenete, Eva
    The preoperative level of physical activity is associated to the postoperative recovery after elective cholecystectomy - A cohort study.2015In: International Journal of Surgery, ISSN 1743-9191, E-ISSN 1743-9159, Vol. 19, p. 35-41Article in journal (Refereed)
    Abstract [en]

    INTRODUCTION: There is an increasing interest in the role of preoperative physical activity for postoperative recovery. The effect of preoperative physical activity and recovery after cholecystectomy is unknown. The aim of this study was to evaluate the association of self-reported leisure-time preoperative physical activity with postoperative recovery and complications after elective cholecystectomy due to gallstone disease.

    METHODS: Prospective observational cohort study with 200 patients scheduled to undergo elective cholecystectomy. Level of self-assessed leisure-time physical activity was compared with recovery.

    RESULTS: Regular physical activity was associated with a higher degree of return to work within three weeks post-operatively (relative chance (RC) 1.26, p = 0.040); with a higher chance of leaving hospital within one day post-op (RC 1.23, p = 0.001), as well as with better mental recovery (RC 1.18, p = 0.049), compared to physically inactive. No statistically significant association was seen with return to work within one week or with self-assessed physical recovery.

    DISCUSSION: In clinical practice, evaluating the patients' level of physical activity is feasible, and may potentially be used to identify patients being more suitable for same-day surgery. Given the study design, the results from this study cannot prove causality.

    CONCLUSION: The present study shows that the preoperative leisure-time physical activity-level, is positively associated with less sick leave, a shorter hospital stay and with better mental recovery, three weeks post-elective cholecystectomy. We recommend assessing the physical activity-level preoperatively for prognostic reasons. If preoperative/postoperative physical training will increase recovery remains to be shown in a randomized controlled study.

  • 237. Palmefors, Henning
    et al.
    DuttaRoy, Smita
    Rundqvist, Bengt
    Börjesson, Mats
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's and Mats Börjesson's research group.
    The effect of physical activity or exercise on key biomarkers in atherosclerosis: a systematic review2014In: Atherosclerosis, ISSN 0021-9150, E-ISSN 1879-1484, Vol. 235, no 1, p. 150-61Article, review/survey (Refereed)
    Abstract [en]

    OBJECTIVE: This systematic review aimed to summarize published papers on the effect of physical activity (PA)/exercise on key atherosclerotic factors in patients with risk factors for or established cardiovascular disease (CVD).

    METHODS: Studies involving PA and cytokines, chemokines, adhesion molecules, CRP and angiogenic factors were searched for in Medline and Cochrane library. Original human studies of more than 2 weeks of PA intervention were included. Study quality was assessed according to the GRADE system of evidence.

    RESULTS: Twenty-eight papers fulfilled the inclusion criteria. PA decreases the cytokines, tumor necrosis factor-a (TNF-a), interleukin-6 (IL-6), and interferon-y IFN-y (high, moderate and low evidence, respectively). The effect of PA on chemokines; stromal derived factor-1 (SDF-1), interleukin-8 (IL-8) (insufficient evidence) and monocyte chemoattractant protein-1 (MCP-1) (low evidence) was inconclusive. Aerobic exercise decreased the adhesion molecules, vascular cell adhesion molecule-1 (VCAM-1) and intercellular adhesion molecule-1 (ICAM-1) (moderate and high evidence, respectively), while effects of PA on E- and P-selectin were inconclusive. PA decreases C-reactive protein (CRP) (high evidence). The angiogenic actors, endothelial progenitor cells (EPCs) are increased (high evidence) and VEGF is decreased (moderate evidence) by PA. The effect of PA on these factors seems to depend on the type and duration of exercise intervention and patient factors, such as presence of ischemia.

    CONCLUSION: As presented in this review, there is a high level of evidence that physical activity positively affects key players in atherosclerosis development. These effects could partly explain the scientifically proven anti-atherogenic effects of PA, and do have important clinical implications.

  • 238. Patrik Johansson, H
    et al.
    Rossander-Hulthén, Lena
    Slinde, Frode
    Ekblom, Björn
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's and Mats Börjesson's research group.
    Accelerometry combined with heart rate telemetry in the assessment of total energy expenditure.2006In: British Journal of Nutrition, ISSN 0007-1145, E-ISSN 1475-2662, Vol. 95, no 3, p. 631-9Article in journal (Refereed)
    Abstract [en]

    The aim of the present study was: (1) to develop a new method for total energy expenditure (TEE) assessment, using accelerometry (ACC) and heart rate (HR) telemetry in combination; (2) to validate the new method against the criterion measure (DLW) and to compare with two of the most common methods, FLEX-HR and ACC alone. In the first part of the study VO(2), HR and ACC counts were measured in twenty-seven subjects during walking and running on a treadmill. Considering the advantages and disadvantages of the HR and ACC methods an analysis model was developed, using ACC at intensities of low and medium levels and HR at higher intensities. During periods of inactivity, RMR is used. A formula for determining TEE from ACC, HR and RMR was developed: TEE = 1.1x(EQ(HR) x TT(HR) + EQ(ACC1) x TT(ACC1) + EQ(ACC2) x TTACC2 + RMR x TT(RMR)). In the validation part of the study a sub-sample of eight subjects wore an accelerometer, HR was logged and TEE was measured for 14 d with the DLW method. Analysis of the Bland-Altman plots with 95 % CI indicates that there are no significant differences in TEE estimated with HR-ACC and ACC alone compared with TEE measured with DLW. It is concluded that the HR-ACC combination as well as ACC alone has potential as a method for assessment of TEE during free-living activities as compared with DLW.

  • 239.
    Rafter, Ingalill
    et al.
    Safety Assessment, AstraZeneca, Södertälje.
    Gråberg, Truls
    Department of Clinical Science, Intervention and Technology (CLINTEC), Division of Surgery, Karolinska Institute at Karolinska University Hospital.
    Kotronen, Anna
    Department of Medicine, University of Helsinki, Helsinki, Finland.
    Strömmer, Lovisa
    Department of Clinical Science, Intervention and Technology (CLINTEC), Division of Surgery, Karolinska Institute at Karolinska University Hospital.
    Mattsson, C. Mikael
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences.
    Kim, Ray W
    Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, MN, USA.
    Ehrenborg, Ewa
    Department of Medicine, Center for Molecular Medicine, Karolinska Institute, Stockholm, Sweden.
    Andersson, Håkan B
    Safety Assessment, AstraZeneca, Södertälje.
    Yki-Järvinen, Hannele
    Department of Medicine, University of Helsinki, Helsinki, Finland.
    Schuppe-Koistinen, Ina
    Safety Assessment, AstraZeneca, Södertälje.
    Ekblom, Björn
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's and Mats Börjesson's research group.
    Cotgreave, Ian
    Safety Assessment, AstraZeneca, Södertälje.
    Glinghammar, Björn
    Safety Assessment, AstraZeneca, Södertälje.
    Isoform-specific alanine aminotransferase measurement candistinguish hepatic from extrahepatic injury in humans2012In: International Journal of Molecular Medicine, ISSN 1107-3756, E-ISSN 1791-244X, Vol. 30, p. 1241-1249Article in journal (Refereed)
    Abstract [en]

    Serum alanine aminotransferase (ALT) is used asa clinical marker to detect hepatic damage and hepatoxicity.Two isoforms of ALT have been identified, ALT1 and ALT2,which have identical enzymatic capacities and are detectedsimultaneously in human serum/plasma using classical clinicalchemical assays. Differences exist in the expression patterns ofthe ALT1 and ALT2 proteins in different organs which suggestthat changes in the proportion of ALT1 and ALT2 in plasmamay arise and reflect damage to different human organs.However, this has not been previously studied due to the lackof a selective methodology that can quantify both ALT1 andALT2 isoforms in the total ALT activity normally measuredin clinical samples. To the best of our knowledge, our currentstudy reveals for the first time, that under 3 different conditionsof liver damage (non-alcoholic fatty liver disease, hepatitis Cand during liver surgery) the leakage of ALT1 activity intoplasma greatly exceeds that of ALT2, and that the measurementof ALT1 during liver damage is equal to the measurement oftotal ALT activity. By contrast, during skeletal muscle injury,induced in volunteers by physical exertion, the leakage ofALT2 exceeds that of ALT1 and the proportion of circulatingALT isoforms changes accordingly. The ALT isoform changesoccurring in plasma reflect previously demonstrated relativecontents of ALT1 and ALT2 activities in human liver and skeletalmuscle. These data suggest that assessing the percentagecontribution of ALT1 and ALT2 activities to total ALT activityin plasma may distinguish hepatic from extrahepatic injuryusing the same standard analytical platform.

  • 240. Reilly, Thomas
    et al.
    Ekblom, Björn
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Björn Ekblom's research group.
    The use of recovery methods post-exercise.2005In: Journal of Sports Sciences, ISSN 0264-0414, E-ISSN 1466-447X, Vol. 23, no 6, p. 619-27Article in journal (Refereed)
    Abstract [en]

    Competitive soccer engages many of the body's systems to a major extent. The musculoskeletal, nervous, immune and metabolic systems are stressed to a point where recovery strategies post-exercise become influential in preparing for the next match. Intense activity at a 7-day training camp causes participants to experience lowered concentrations of non-killer cells and T-helper cells. Two consecutive games in 24 h produce disturbances in the testosterone-cortisol ratio. When competitive schedules are congested, the recovery process should be optimized for performance capabilities to be restored to normal as soon as possible. There is evidence that glycogen stores are reduced near to depletion at the end of a soccer game and that a diet high in carbohydrates can aid recovery. Water alone is not the best means of restoring body fluids, since carbohydrate-electrolyte drinks display better intestinal absorption and reduce urine output. Some relief from muscle soreness may be achieved by means of a warm-down. Deep-water running regimens can replace conventional physical training in the days after competition. Massage, cryotherapy and alternative therapies have not been shown to be consistently effective. It is concluded that optimizing recovery post-exercise depends on a combination of factors that incorporate a consideration of individual differences and lifestyle factors. The procedures to facilitate recovery processes should start immediately the game or training finishes. Match administrators and tournament planners should consider the stressful consequences for players in periods of congested fixtures and alleviate the physiological strain as far as possible by allowing 72 h between competitive games. This frequency of competition is unlikely to be sustainable in the long term.

  • 241. Rickenlund, Anette
    et al.
    Carlström, Kjell
    Ekblom, Björn
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's and Mats Börjesson's research group.
    Brismar, Torkel B
    Von Schoultz, Bo
    Hirschberg, Angelica Lindén
    Effects of oral contraceptives on body composition and physical performance in female athletes.2004In: Journal of Clinical Endocrinology and Metabolism, ISSN 0021-972X, E-ISSN 1945-7197, Vol. 89, no 9, p. 4364-70Article in journal (Refereed)
    Abstract [en]

    Menstrual disturbances are common among female athletes, and oral contraceptives (OCs) are often recommended as estrogen substitution. However, there is little information about the effects of OC use in athletes, and there is great concern that OCs might impair physical performance. The aim of this study was to investigate the effects of OC use on body composition and physical performance in female athletes. Twenty-six endurance athletes (13 with oligo-/amenorrhea and 13 regularly menstruating athletes) and 12 sedentary controls were examined before and after 10 months of treatment with a low dose, monophasic, combined OC. Significant changes in body composition were recorded in the athletes, but not in the controls. There was an increase in weight and fat mass only in athletes with oligo-/amenorrhea. These changes were associated with a decrease in ovarian androgens. OC treatment also increased bone mineral density, with the largest increase in athletes with a low bone mineral density at baseline. Despite significant changes in body composition, little impact on physical performance was recorded. We have demonstrated that OC treatment in female athletes has predominantly beneficial effects on body composition without adverse effects on physical performance and could be used for the prevention of osteoporosis in athletic amenorrhea. However, it cannot be excluded that a marked increase in fat mass might have unfavorable effects for athletic performance in individual women.

  • 242. Rickenlund, Anette
    et al.
    Carlström, Kjell
    Ekblom, Björn
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Björn Ekblom's research group.
    Brismar, Torkel B
    von Schoultz, Bo
    Hirschberg, Angelica Lindén
    Hyperandrogenicity is an alternative mechanism underlying oligomenorrhea or amenorrhea in female athletes and may improve physical performance.2003In: Fertility and Sterility, ISSN 0015-0282, E-ISSN 1556-5653, Vol. 79, no 4, p. 947-55Article in journal (Refereed)
    Abstract [en]

    OBJECTIVE: To evaluate endocrine mechanisms underlying oligomenorrhea or amenorrhea in female athletes. DESIGN: Cross-sectional study. SETTING: Women's health clinical research unit at a university hospital. PATIENT(S): Age- and BMI-matched groups of athletes active in endurance sports with and without menstrual disturbances and regularly cycling sedentary controls. INTERVENTION(S): Groups were compared with respect to endocrine status, body composition, and physical performance. MAIN OUTCOME MEASURE(S): Identification of a subgroup of oligomenorrheic or amenorrheic athletes with increased androgen levels and anabolic body composition. RESULT(S): A subgroup of 8 of 25 athletes with menstrual disturbances had significantly higher serum levels of free and total testosterone, androstenedione, LH-FSH ratio, and lower SHBG levels than did all other groups. Other oligomenorrheic or amenorrheic athletes had normal values comparable to those in regularly menstruating athletes and controls. The hyperandrogenic subgroup showed a more anabolic body composition, with higher total bone mineral density and upper-lower fat mass ratio than did oligomenorrheic or amenorrheic athletes with normal androgen levels. The hyperandrogenic subgroup had the highest VO2 max and the highest performance values in general. CONCLUSION(S): Menstrual disturbances in female athletes are often explained as a consequence of hypothalamic inhibition and caloric deficiency. We suggest that essential hyperandrogenism is an alternative mechanism underlying oligomenorrhea or amenorrhea in some female athletes and may imply an advantage for physical performance.

  • 243.
    Rosdahl, Hans
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, The Laboratory of Applied Sports Science (LTIV). Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, The Research Unit for Movement, Health and Environment. Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Laboratory for Biomechanics and Motor Control.
    Gullstrand, Lennart
    Salier Eriksson, Jane
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, The Research Unit for Movement, Health and Environment.
    Johansson, Patrik
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's and Mats Börjesson's research group.
    Schantz, Peter
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, The Research Unit for Movement, Health and Environment.
    Evaluation of the Oxycon Mobile metabolic system against the Douglas bag method.2010In: European Journal of Applied Physiology, ISSN 1439-6319, E-ISSN 1439-6327, Vol. 109, no 2, p. 159-171Article in journal (Refereed)
    Abstract [en]

    The aim of this study was to evaluate two versions of the Oxycon Mobile portable metabolic system (OMPS1 and OMPS2) in a wide range of oxygen uptake, using the Douglas bag method (DBM) as criterion method. The metabolic variables VO2, VCO2, respiratory exchange ratio and VE were measured during submaximal and maximal cycle ergometer exercise with sedentary, moderately trained individuals and athletes as participants. Test-retest reliability was investigated using the OMPS1. The coefficients of variation varied between 2 and 7% for the metabolic parameters measured at different work rates and resembled those obtained with the DBM. With the OMPS1, systematic errors were found in the determination of VO2 and VCO2. At submaximal work rates VO2 was 6-14% and VCO2 5-9% higher than with the DBM. At VO2max both VO2 and VCO2 were slightly lower as compared to DBM (-4.1 and -2.8% respectively). With OMPS2, VO2 was determined accurately within a wide measurement range (about 1-5.5 L min(-1)), while VCO2 was overestimated (3-7%). VE was accurate at submaximal work rates with both OMPS1 and OMPS2, whereas underestimations (4-8%) were noted at VO2max. The present study is the first to demonstrate that a wide range of VO2 can be measured accurately with the Oxycon Mobile portable metabolic system (second generation). Future investigations are suggested to clarify reasons for the small errors noted for VE and VCO2 versus the Douglas bag measurements, and also to gain knowledge of the performance of the device under applied and non-laboratory conditions.

  • 244. Rosenbloom, Christine A
    et al.
    Loucks, Anne B
    Ekblom, Björn
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Björn Ekblom's research group.
    Special populations: the female player and the youth player.2006In: Journal of Sports Sciences, ISSN 0264-0414, E-ISSN 1466-447X, Vol. 24, no 7, p. 783-93Article in journal (Refereed)
    Abstract [en]

    Females and youth are frequently described as "special" populations in football literature, but together these two populations outnumber male players. What makes females "special" is that they tend to eat less when training and competing than their male counterparts, leading to lower intakes of energy, carbohydrate, and some nutrients. Youth football players are special in regard to energy and nutrient requirements to promote growth and development, as well as to fuel sport. There is limited research on the dietary habits of these two populations, but the available literature suggests that many female and youth players need to increase carbohydrate intake, increase fluid intake, and develop dietary habits to sustain the demands of training and competition.

  • 245. Ryynänen, Jaakko
    et al.
    Leventer, Louis
    Peterson, Lars
    Kautiainen, Hannu
    Karlsson, Jon
    Fuller, Colin
    Börjesson, Mats
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's and Mats Börjesson's research group.
    Combining data from injury surveillance and video analysis studies: an evaluation of three FIFA World Cups2014In: Global Journal of Medical Research, ISSN 2249-4618, Vol. 14, no 3, p. 1-9Article in journal (Refereed)
    Abstract [en]

    Objective: To analyze the playing actions and match circumstances which involve physical contact between players and lead to injuries in men’s World Cup football.

    Design: Prospective injury surveillance and video analysis of matches in three FIFA World Cups.

    Setting: 2002, 2006 and 2010 FIFA World Cups™.

    Participants: Players and team physicians at the 2002, 2006 and 2010 FIFA World Cups™.

    Main outcome measures: Contact injury risk incidents linked with an injury and contact injury incidents without linkable injury.

    Results: Three hundred and four contact injuries were reported and 671 contact injury risk incidents were identified from the video recordings. One hundred and twenty-eight (42.1%) of the reported contact injuries were linkable with a contact injury risk incident.

  • 246.
    Sahlin, Kent
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Research group for Mitokondriell funktion och metabolisk kontroll.
    Shabalina, Irina G
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology. Stockholm University.
    Mattsson, C Mikael
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's research group.
    Bakkman, Linda
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology. Karolinska Institutet.
    Fernström, Maria
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology. Karolinska Institutet.
    Rozhdestvenskaya, Zinaida
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology.
    Enqvist, Jonas K
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's research group.
    Nedergaard, Jan
    Stockholm University.
    Ekblom, Björn T
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's research group.
    Tonkonogi, Michail
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology. University of Dalarna.
    Ultra-endurance exercise increases the production of reactive oxygen species in isolated mitochondria from human skeletal muscle.2010In: Journal of applied physiology, ISSN 8750-7587, E-ISSN 1522-1601, Vol. 108, no 4, p. 780-787Article in journal (Refereed)
    Abstract [en]

    Exercise-induced oxidative stress is important for the muscular adaptation to training but may also cause muscle damage. We hypothesized that prolonged exercise would increase mitochondrial production of reactive oxygen species (ROS) measured in vitro and that this correlates with oxidative damage. Eight male athletes (24-32 years) performed ultra-endurance exercise (kayaking/running/cycling) with an average work intensity of 55% VO2peak for 24 h. Muscle biopsies were taken from vastus lateralis before exercise, immediately after exercise and after 28 h of recovery. The production of H2O2 was measured fluorometrically in isolated mitochondria with the Amplex red and peroxidase system. Succinate-supported mitochondrial H2O2 production was significantly increased after exercise (73% higher, P=0.025) but restored to the initial level at recovery. Plasma level of free fatty acids (FFA) increased 4-fold and exceeded 1.2 mmol l(-1) during the last 6 h of exercise. Plasma FFA at the end of exercise was significantly correlated to mitochondrial ROS production (r=0.74, P<0.05). Mitochondrial content of 4-hydroxy-nonenal-adducts (a marker of oxidative damage) was increased only after recovery and was not correlated with mitochondrial ROS production. Total thiol-group level and glutathione peroxidase activity were elevated after recovery. In conclusion: ultra-endurance exercise increases ROS production in isolated mitochondria but this is reversed after 28 h recovery. Mitochondrial ROS production was not correlated with oxidative damage of mitochondrial proteins, which was increased at recovery but not immediately after exercise. Key words: antioxidative defence, fatty acids, oxidative stress.

  • 247.
    Samuelsson, Hedvig
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences.
    Moberg, Marcus
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Eva Blomstrand's research group.
    Apró, William
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's research group.
    Ekblom, Björn
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's research group.
    Blomstrand, Eva
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Eva Blomstrand's research group.
    Intake of branched-chain or essential amino acids attenuates the elevation in muscle levels of PGC-1α4 mRNA caused by resistance exercise.2016In: American Journal of Physiology. Endocrinology and Metabolism, ISSN 0193-1849, E-ISSN 1522-1555, Vol. 311, no 1, p. E246-E251Article in journal (Refereed)
    Abstract [en]

    The transcriptional co-activator PGC-1α is recognized as the master regulator of mitochondrial biogenesis. However, recently a novel isoform, PGC-1α4 that specifically regulates muscle hypertrophy was discovered. Since stimulation of mTORC1 activity is tightly coupled to hypertrophy, we hypothesized that activation of this pathway would upregulate PGC-1α4. Eight male subjects performed heavy resistance exercise (10 x 8-12 repetitions at ~75% of 1RM in leg press) on four different occasions, ingesting in random order a solution containing essential amino acids (EAA), branched-chain amino acids (BCAA), leucine or flavored water (placebo) during and after the exercise. Biopsies were taken from the vastus lateralis muscle before and immediately after exercise, as well as following 90 and 180 min of recovery. Signaling through mTORC1, as reflected in S6K1 phosphorylation, was stimulated to a greater extent by the EAA and BCAA than the leucine or placebo supplements. Unexpectedly, intake of EAA or BCAA attenuated the stimulatory effect of exercise on PGC-1α4 expression by ~50% (from a 10-fold to 5-fold increase with BCAA and EAA, P<0.05) 3 h after exercise, whereas intake of leucine alone did not reduce this response. The 60% increase (P<0.05) in the level of PGC-1α1 mRNA 90 min after exercise was uninfluenced by amino acid intake. Muscle glycogen levels were reduced and AMPKα2 activity and phosphorylation of p38 MAPK enhanced to the same extent with all four supplements. In conclusion, induction of PGC-1α4 does not appear to regulate the nutritional (BCAA or EAA) mediated activation of mTORC1 in human muscle.

  • 248. Sandström, Göran
    et al.
    Rödjer, Stig
    Kaijser, Bertil
    Börjesson, Mats
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's and Mats Börjesson's research group.
    Helicobacter pylori Antibodies and Iron Deficiency in Female Adolescents.2014In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 9, no 11, p. e113059-Article in journal (Refereed)
    Abstract [en]

    OBJECTIVE: Iron deficiency (ID) is a common clinical problem worldwide, affecting primarily females. Helicobacter pylori (HP) infection has been shown to be associated with ID. The objective of this study was to define the prevalence of HP antibodies in female adolescents, and to find out if there was a correlation between HP infection and ID. The secondary aim was to study if regularly performed sporting activity, have any association to HP infection, in itself.

    DESIGN: A controlled clinical trial.

    SETTING: A senior high school in Gothenburg, Sweden.

    SUBJECTS: All female athletes at a senior high school for top-level athletes were offered to take part, and 56 athletes took part in the study. The control group consisted of a random sample of age-matched non-athlete students of which 71 entered the study.

    MAIN OUTCOME MEASURES: Iron deficiency (ID) and iron deficiency anaemia (IDA) were defined by the use of levels of haemoglobin, serum iron, total iron-binding capacity, transferrin saturation, and serum ferritin, as previously described. HP IgG-antibodies were detected by ELISA.

    RESULTS: 18 of 127 (14%) adolescent females had antibodies against HP. Only 3% had IDA, while 50% had ID. In total, 66% of the HP positive females had ID compared to 48% of the negative females (p = 0.203). No correlation between sporting activity and HP infection was found. Regarding ethnicity, 11/28 of subjects from medium-high risk areas were HP-positive, compared to 7/99 coming from low-risk areas (p<0.001).

    CONCLUSION: The main finding of this study is that the prevalence of HP IgG antibodies was 14% in adolescent females. We could not find any difference regarding frequency of ID and IDA, between HP positive and negative individuals. Ethnicity is of great importance for the risk of HP infection, while sporting activity itself seems to have no association to HP-infection.

  • 249. Schiffer, Tomas A
    et al.
    Ekblom, Björn
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's and Mats Börjesson's research group.
    Lundberg, Jon O
    Weitzberg, Eddie
    Larsen, Filip J
    Dynamic regulation of metabolic efficiency explains tolerance to acute hypoxia in humans.2014In: The FASEB Journal, ISSN 0892-6638, E-ISSN 1530-6860, Vol. 28, no 10, p. 4303-11Article in journal (Refereed)
    Abstract [en]

    The maximum power principle dictates that open biological systems tend to self-organize to a level of efficiency that allows maximal power production. Applying this principle to cellular energetics and whole-body physiology would suggest that for every metabolic challenge, an optimal efficiency exists that maximizes power production. On exposure to hypoxia, it would be favorable if metabolic efficiency would rapidly adjust so as to better preserve work performance. We tested this idea in humans by measuring metabolic efficiency and exercise tolerance under normoxic (Fio2=20.9%) and hypoxic (Fio2=16%) conditions, where Fio2 is fraction of inhaled oxygen. The results were compared with respirometric analyses of skeletal muscle mitochondria from the same individuals. We found that among healthy trained subjects (n=14) with a wide range of metabolic efficiency (ME), those with a high ME during normoxic exercise were able to better maintain exercise capacity (Wmax) in hypoxia. On hypoxic exposure, these subjects acutely decreased their efficiency from 19.2 to 17.4%, thereby likely shifting it closer to a degree of efficiency where maximal power production is achieved. In addition, mitochondria from these subjects had a lower intrinsic respiration compared to subjects that showed a large drop in Wmax in hypoxia An acute shift in efficiency was also demonstrated in isolated mitochondria exposed to physiological levels of hypoxia as P/O ratio increased from 0.9 to 1.3 with hypoxic exposure. These findings suggest the existence of a physiological adaptive response by which metabolic efficiency is dynamically optimized to maximize power production.-Schiffer, T. A., Ekblom, B., Lundberg, J. O., Weitzberg, E., Larsen, F. J. Dynamic regulation of metabolic efficiency explains tolerance to acute hypoxia in humans.

  • 250. Schiffer, Tomas A
    et al.
    Peleli, Maria
    Sundqvist, Michaela L
    Ekblom, Björn
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's research group.
    Lundberg, Jon O
    Weitzberg, Eddie
    Larsen, Filip J
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Research group for Mitokondriell funktion och metabolisk kontroll.
    Control of Human Energy Expenditure by Cytochrome C Oxidase Subunit IV-2.2016In: American Journal of Physiology - Cell Physiology, ISSN 0363-6143, E-ISSN 1522-1563, Vol. 311, no 3, p. C452-C461Article in journal (Refereed)
    Abstract [en]

    Resting metabolic rate (RMR) in human shows pronounced individual variations, but the underlying molecular mechanism remains elusive. Cytochrome C oxidase (COX) plays a key role in control of metabolic rate and recent studies of the subunit 4 isoform 2 (COX IV-2) indicate involvement in the cellular response to hypoxia and oxidative stress. We evaluated whether the COX subunit IV isoform composition may explain the pronounced individual variations in resting metabolic rate (RMR). RMR was determined in healthy humans by indirect calorimetry and correlated to levels of COX IV-2 and COX IV-1 in Vastus Lateralis. Over expression and knock down of the COX IV isoforms were performed in primary myotubes followed by evaluation of the cell respiration and production of reactive oxygen species. Here we show that COX IV-2 protein is constitutively expressed in human skeletal muscle and strongly correlated to RMR. Primary human myotubes overexpressing COX IV-2 displayed markedly (>60%) lower respiration, reduced (>50%) cellular H2O2 production, higher resistance towards both oxidative stress and severe hypoxia compared to control cells. These results suggest an important role of isoform COX IV-2 in the control of energy expenditure, hypoxic tolerance and mitochondrial ROS homeostasis in humans.

23456 201 - 250 of 267
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