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  • 451.
    Psilander, Niklas
    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.
    Frank, Per
    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.
    Sahlin, Kent
    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.
    Exercise with low glycogen increases PGC-1α gene expression in human skeletal muscle.2013In: European Journal of Applied Physiology, ISSN 1439-6319, E-ISSN 1439-6327, Vol. 113, no 4, p. 951-963Article in journal (Refereed)
    Abstract [en]

    Recent studies suggest that carbohydrate restriction can improve the training-induced adaptation of muscle oxidative capacity. However, the importance of low muscle glycogen on the molecular signaling of mitochondrial biogenesis remains unclear. Here, we compare the effects of exercise with low (LG) and normal (NG) glycogen on different molecular factors involved in the regulation of mitochondrial biogenesis. Ten highly trained cyclists (VO(2max) 65 ± 1 ml/kg/min, W (max) 387 ± 8 W) exercised for 60 min at approximately 64 % VO(2max) with either low [166 ± 21 mmol/kg dry weight (dw)] or normal (478 ± 33 mmol/kg dw) muscle glycogen levels achieved by prior exercise/diet intervention. Muscle biopsies were taken before, and 3 h after, exercise. The mRNA of peroxisome proliferator-activated receptor-γ coactivator-1 was enhanced to a greater extent when exercise was performed with low compared with normal glycogen levels (8.1-fold vs. 2.5-fold increase). Cytochrome c oxidase subunit I and pyruvate dehydrogenase kinase isozyme 4 mRNA were increased after LG (1.3- and 114-fold increase, respectively), but not after NG. Phosphorylation of AMP-activated protein kinase, p38 mitogen-activated protein kinases and acetyl-CoA carboxylase was not changed 3 h post-exercise. Mitochondrial reactive oxygen species production and glutathione oxidative status tended to be reduced 3 h post-exercise. We conclude that exercise with low glycogen levels amplifies the expression of the major genetic marker for mitochondrial biogenesis in highly trained cyclists. The results suggest that low glycogen exercise may be beneficial for improving muscle oxidative capacity.

  • 452.
    Psilander, Niklas
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology.
    Petré, Henrik
    Swedish School of Sport and Health Sciences, GIH.
    Löfving, Pontus
    Swedish School of Sport and Health Sciences, GIH.
    Överdriven oro för kombinationsträning2015In: Svensk Idrottsforskning: Organ för Centrum för Idrottsforskning, ISSN 1103-4629, no 1, p. 8-13Article in journal (Other academic)
    Abstract [sv]

    Många som vill öka sin muskelmassa och styrka undviker uthållighetsträning. En vanlig åsikt är nämligen att man inte bör kombinera styrke ochuthållighetsträning. Den uppfattningen har däremot inget stöd i den senaste forskningen.

  • 453.
    Psilander, Niklas
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Research group for Mitokondriell funktion och metabolisk kontroll.
    Sahlin, Kent
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Research group for Mitokondriell funktion och metabolisk kontroll.
    Nya forskningsrön kan ge bättre träningsmetoder2013In: Svensk Idrottsforskning: Organ för Centrum för Idrottsforskning, ISSN 1103-4629, Vol. 22, no 1, p. 41-44Article in journal (Other academic)
    Abstract [sv]

    Det finns många uppfattningar om hur man bäst förbättrar konditionen. Ofta förlitar idrottare sig mer på beprövad erfarenhet än på vetenskapen. Men under de senaste åren har idrottsforskningen, med hjälp av molekylärbiologisk teknik, gjort framsteg i hur man kan effektivisera sin träning genom kosten och sättet att träna.

  • 454.
    Psilander, Niklas
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Research group for Mitokondriell funktion och metabolisk kontroll.
    Wang, Li
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Research group for Mitokondriell funktion och metabolisk kontroll.
    Westergren, Jens
    Tonkonogi, Michail
    Sahlin, Kent
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Research group for Mitokondriell funktion och metabolisk kontroll.
    Mitochondrial gene expression in elite cyclists: effects of high-intensity interval exercise.2010In: European Journal of Applied Physiology, ISSN 1439-6319, E-ISSN 1439-6327, Vol. 110, no 3, p. 597-606Article in journal (Refereed)
    Abstract [en]

    Little is known about the effect of training on genetic markers for mitochondrial biogenesis in elite athletes. We tested the hypothesis that low-volume sprint interval exercise (SIE) would be as effective as high-volume interval exercise (IE). Ten male cyclists competing on national elite level (W (max) 403 ± 13 W, VO(2peak) 68 ± 1 mL kg(-1) min(-1)) performed two interval exercise protocols: 7 × 30-s "all-out" bouts (SIE) and 3 × 20-min bouts at ~87% of VO(2peak) (IE). During IE, the work was eightfold larger (1,095 ± 43 vs. 135 ± 5 kJ) and the exercise duration 17 times longer (60 vs. 3.5 min) than during SIE. Muscle samples were taken before and 3 h after exercise. The mRNA of upstream markers of mitochondrial biogenesis [peroxisome proliferator-activated receptor-γ coactivator-1 (PGC-1α), PGC-1α-related coactivator (PRC) and peroxisome proliferator-activated receptor δ (PPARδ)] increased to the same extent after SIE and IE (6-, 1.5- and 1.5-fold increase, respectively). Of the downstream targets of PGC-1α, mitochondrial transcription factor A (Tfam) increased only after SIE and was significantly different from that after IE (P < 0.05), whereas others increased to the same extent (pyruvate dehydrogenase kinase, PDK4) or was unchanged (nuclear respiratory factor 2, NRF2). We conclude that upstream genetic markers of mitochondrial biogenesis increase in a similar way in elite athletes after one exercise session of SIE and IE. However, since the volume and duration of work was considerably lower during SIE and since Tfam, the downstream target of PGC-1α, increased only after SIE, we conclude that SIE might be a time-efficient training strategy for highly trained individuals.

  • 455.
    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.

  • 456.
    Rahman, Md Shafiqur
    et al.
    Karolinska Institutet.
    Helgadóttir, Björg
    Karolinska Institutet.
    Hallgren, Mats
    Karolinska Institutet.
    Forsell, Yvonne
    Karolinska Institutet.
    Stubbs, Brendon
    King's College London, UK..
    Vancampfort, Davy
    KU Leuven, Belgium.
    Ekblom, Örjan
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology.
    Cardiorespiratory fitness and response to exercise treatment in depression.2018In: BJPsych open, ISSN 2056-4724, Vol. 4, no 5, p. 346-351Article in journal (Refereed)
    Abstract [en]

    Background: Exercise improves cardiorespiratory fitness (CRF) and reduces depressive symptoms in people with depression. It is unclear if changes in CRF are a predictor of the antidepressant effect of exercise in people with depression.

    Aims: To investigate whether an increase in CRF is a predictor of depression severity reduction after 12 weeks of exercise (trial registration: DRKS study ID, DRKS00008745).

    Method: The present study includes participants who took part in vigorous (n = 33), moderate (n = 38) and light (n = 39) intensity exercise and had CRF information (as predicted maximal oxygen uptake, O2max) collected before and after the intervention. Depression severity was measured with the Montgomery-Åsberg Depression Rating Scale (MADRS). O2max (L/min) was assessed with the Åstrand-Rhyming submaximal cycle ergometry test. The main analysis was conducted pooling all exercise intensity groups together.

    Results: All exercise intensities improved O2max in people with depression. Regardless of frequency and intensity of exercise, an increase in post-treatment O2max was significantly associated with reduced depression severity at follow-up (B = -3.52, 95% CI -6.08 to -0.96); adjusting for intensity of exercise, age and body mass index made the association stronger (B = -3.89, 95% CI -6.53 to -1.26). Similarly, increased O2max was associated with higher odds (odds ratio = 3.73, 95% CI 1.22-11.43) of exercise treatment response (≥50% reduction in MADRS score) at follow-up.

    Conclusions: Our data suggest that improvements in O2max predict a greater reduction in depression severity among individuals who were clinically depressed. This finding indicates that improvements in O2max may be a marker for the underpinning biological pathways for the antidepressant effect of exercise.

    Declaration of interest: None.

  • 457. Ranchordas, M K
    et al.
    Blomstrand, Eva
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Eva Blomstrand's research group.
    Calder, P C
    Burke, L M
    Stear, S J
    Castell, L M
    A-z of nutritional supplements: dietary supplements, sports nutrition foods and ergogenic aids for health and performance--part 23.2011In: British Journal of Sports Medicine, ISSN 0306-3674, E-ISSN 1473-0480, Vol. 45, no 10, p. 830-1Article in journal (Other academic)
  • 458. 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.

  • 459. 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.

  • 460. 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.

  • 461.
    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.

  • 462.
    Rosdahl, Hans
    et al.
    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.
    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.
    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.
    Validation of data collected with mobile metabolic measurement systems over time during active commuting2016Conference paper (Refereed)
    Abstract [en]

    Introduction

    With the aim of attaining valid descriptions of metabolic demands during active commuting in greater Stockholm new approaches have been used. We have previously reported evaluations of a mobile metabolic measurement system both in the laboratory (Rosdahl et al. 2010) and during simulated field conditions, including check of stability over time (Salier-Eriksson et al. 2012). However, to be confident with the validity of the metabolic data collected over time during mobile field conditions we have used new approaches. 

    Methods

    During the period of data collection in the field with the mobile metabolic system (Oxycon Mobile, JLAB 5.21, CareFusion, Germany) this was controlled once by the manufacturer and 11 times in our own laboratory using a commercially available metabolic calibrator (Vacumed, syringe No.1750 and mass flow controller No. 17052, Ventura, CA, USA).  On each occasion VO2 and VCO2 were checked between 1 - 4 L/min with the corresponding VE at 40-160 L/minute and tidal volume at 2 L. The calibration information (offset, gain and delay time) from the O2 and CO2 analyzers and volume sensor, being collected pre and post the field commuting tests, was analyzed. Additionally, the results of each experiment was critically examined in several means including an inspection of parallelism in heart rate and VO2. 

    Results and Discussion

    As examined with the metabolic calibrator, all parameters (VO2, VCO2, RER and VE) measured by the mobile metabolic system were in general well within the boundaries of acceptance. Adequate stability of the O2 and CO2 analyzers and volume sensors for the time duration of each experiment was confirmed by small differences in the pre- and post-calibration factors. Based on two researchers´ ocular inspections of heart rate and oxygen uptake recordings during active commuting, all but one were rated as generally parallel, and thus passed this type of check of the field measurements. Overall, the present investigation favors that data collected over time with a mobile metabolic system can be validated by a combination of metabolic calibrator measurements, analyses of calibration information and a critical examination of the variables from each single measurement.

    References

    Rosdahl, H., Gullstrand, L., Salier Eriksson, J., Johansson, P. & Schantz, P. 2010. Evaluation of the Oxycon Mobile metabolic system against the Douglas bag method. Eur J Appl Physiol 109 (2):159-71.

    Salier Eriksson, J., Rosdahl, H. & Schantz, P. 2012. Validity of the Oxycon Mobile metabolic system under field measuring conditions. Eur J Appl Physiol, 112 (1): 345-355.

    Huszczuk, A., Whipp, B.J and Wasserman, K. 1990. A respiratory gas exchange simulator for routine calibration in metabolic studies. Eur. Respir. J. 3:465-468.

  • 463.
    Rosdahl, Hans
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, The Research Unit for Movement, Health and Environment.
    Salier-Eriksson, Jane
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, The Research Unit for Movement, Health and Environment.
    Schantz, Peter
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, The Research Unit for Movement, Health and Environment.
    Measurements of Metabolic Profiles of Commuting Pedestrians and Cyclists using Validated Indirect Calorimetry2010In: Proceedings from The 3rd International Congress on Physical Activity and Public Health, Toronto, May, 5-8, 2010, 2010, p. 36-Conference paper (Other academic)
  • 464. 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.

  • 465. Rundqvist, Håkan C
    et al.
    Esbjörnsson, Mona
    Rooyackers, Olav
    Apro, 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.
    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.
    Österlund, Ted
    Jansson, Eva
    Amino Acid Transport after Sprint Exercise and Oral Amino Acids: 90 Board #6 June 1, 92016In: Medicine & Science in Sports & Exercise: Volume 48(5S) Supplement 1, May 2016, p 5, 2016, Vol. 48, no 5 Suppl 1, p. 5-Conference paper (Other academic)
    Abstract [en]

    PURPOSE: To study if oral ingestion of essential amino acids (oral EAA) increases the amino acid transporter SNAT2, Akt/mTOR signaling and muscle protein synthesis (MPS) after sprint exercise.

    METHODS: 12 healthy subjects performed three 30-s sprints with 20 minutes rest in between. Subjects consumed EAA + maltodextrin solution or flavoured water (placebo) during the sprint exercise up to 15 min after the last sprint in a randomized order with one month interval. In vivo MPS rate was measured using a stable isotope technique. Subject received a stable isotope of phenylalanine (D5-phenylalanine) to label the precursor pool for protein synthesis. Continuous infusion started before the first sprint and was ended 200 min after the last sprint. Two post exercise biopsies (vastus lateralis) were obtained 80 min and 200 min after last sprint. The amount of labelled phenylalanine incorporated into muscle protein over these 2 hours represents the in vivo MPS rate and was expressed as fractional synthesis rate (FSR %) calculated by dividing amount of labelled phenylalanine incorporated during these 2 hours by the amount in the free amino acid (precursor) plasma pool. Biopsies were also analyzed for Akt/mTOR signaling and SNAT2 amino acid transporter by Western blot and for SNAT2 gene expression by real-time PCR. Blood samples were analyzed for amino acids, glucose, lactate, and insulin. Four subjects, involuntary vomiting after exercise during EAA condition, showed a minor increase in plasma leucine and were presented separately.

    RESULTS: Non-vomiting subjects (n=8): The expression of the amino acid transporter SNAT2 was higher both at the protein (P<0.05) and the mRNA (P<0.001) level after EEA than after placebo. Fold increase for phosphorylated Akt, mTOR and p70 was 1.7-3.6 (P<0.01 - P<0.001) comparing EAA with placebo. FSR % after EEA was increased by 25 % (P=0.02) compared to placebo. None of these variables were significantly increased in the subjects who vomited.

    CONCLUSION: Oral EAA increased MPS after sprint exercise. Enhanced capacity for amino acid transport and subsequent enhanced Akt/mTOR signaling are suggested to mediate the increased MPS.

  • 466.
    Rundqvist, Håkan Claes
    et al.
    Karolinska Institutet .
    Esbjörnsson, Mona
    Karolinska Institutet .
    Rooyackers, Olav
    Huddinge University Hospital .
    Osterlund, Ted
    Karolinska Institutet.
    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, Eva Blomstrand'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.
    Jansson, Eva
    Karolinska Institutet .
    Influence of nutrient ingestion on amino acid transporters and protein synthesis in human skeletal muscle after sprint exercise2017In: Journal of applied physiology, ISSN 8750-7587, E-ISSN 1522-1601, Vol. 123, no 6, p. 1501-1515Article in journal (Refereed)
    Abstract [en]

    Nutrient ingestion is known to increase the exercise-induced stimulation of muscle protein synthesis following resistance exercise. Less is known about the effect of nutrients on muscle protein synthesis following sprint exercise. At two occasions separated by one month, twelve healthy subjects performed three 30-s sprints with 20-min rest between bouts. In randomized order, they consumed a drink with essential amino acids and maltodextrin (nutrient) or flavored water (placebo). Muscle biopsies were obtained 80 and 200 min after the last sprint and blood samples were taken repeatedly during the experiment. Fractional synthetic rate (FSR) was measured by continuous infusion of L-[(2)H5]-phenylalanine up to 200 min postexercise. The mRNA and protein expression of SNAT2 were both 1.4-fold higher (P < 0.05) after nutrient intake compared to placebo at 200 min postexercise. Phosphorylated Akt, mTOR and p70S6k was 1.7- to 3.6-fold higher (P<0.01) 80 min after the last sprint with nutrient ingestion as compared to placebo. In addition, FSR was higher (P<0.05) with nutrients when plasma phenylalanine (FSRplasma) was used as a precursor, but not when intracellular phenylalanine (FSRmuscle) was used. Significant correlations were also found between FSRplasma on the one hand and plasma leucine and serum insulin on the other hand in the nutrient condition. The results show that nutrient ingestion induces the expression of the amino acid transporter SNAT2, stimulates Akt/mTOR signaling and most likely the rate of muscle protein synthesis following sprint exercise.

  • 467. 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.

  • 468. Râdegran, Göran
    et al.
    Blomstrand, Eva
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Eva Blomstrand's research group.
    Saltin, Bengt
    Peak muscle perfusion and oxygen uptake in humans: importance of precise estimates of muscle mass.1999In: Journal of applied physiology, ISSN 8750-7587, E-ISSN 1522-1601, Vol. 87, no 6, p. 2375-80Article in journal (Refereed)
    Abstract [en]

    The knee extensor exercise model was specifically developed to enable in vivo estimates of peak muscle blood flow and O(2) uptake in humans. The original finding, using thermodilution measurements to measure blood flow in relation to muscle mass [P. Andersen and B. Saltin. J. Physiol. (Lond.) 366: 233-249, 1985], was questioned, however, as the measurements were two- to threefold higher than those previously obtained with the (133)Xe clearance and the plethysmography technique. As thermodilution measurements have now been confirmed by other methods and independent research groups, we aimed to address the impact of muscle mass estimates on the peak values of muscle perfusion and O(2) uptake. In the present study, knee extensor volume was determined from multiple measurements with computer tomography along the full length of the muscle. In nine healthy humans, quadriceps muscle volume was 2.36 +/- 0.17 (range 1. 31-3.27) liters, corresponding to 2.48 +/- 0.18 (range 1.37-3.43) kg. Anthropometry overestimated the muscle volume by approximately 21-46%, depending on whether quadriceps muscle length was estimated from the patella to either the pubic bone, inguinal ligament, or spina iliaca anterior superior. One-legged, dynamic knee extensor exercise up to peak effort of 67 +/- 7 (range 55-100) W rendered peak values for leg blood flow (thermodilution) of 5.99 +/- 0.66 (range 4.15-9.52) l/min and leg O(2) uptake of 856 +/- 109 (range 590-1,521) ml/min. Muscle perfusion and O(2) uptake reached peak values of 246 +/- 24 (range 149-373) and 35.2 +/- 3.7 (range 22.6-59. 6) ml. min(-1). 100 g muscle(-1), respectively. These peak values are approximately 19-33% larger than those attained by applying anthropometric muscle mass estimates. In conclusion, the present findings emphasize that peak perfusion and O(2) uptake in human skeletal muscle may be up to approximately 30% higher than previous anthropometric-based estimates that use equivalent techniques for blood flow measurements.

  • 469.
    Sahlin, Kent
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Research group for Mitokondriell funktion och metabolisk kontroll.
    Boosting fat burning with carnitine: an old friend comes out from the shadow.2011In: Journal of Physiology, ISSN 0022-3751, E-ISSN 1469-7793, Vol. 589, no Pt 7, p. 1509-10Article in journal (Refereed)
  • 470.
    Sahlin, Kent
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Research group for Mitokondriell funktion och metabolisk kontroll.
    Comments on Point: Counterpoint: Muscle lactate and H⁺ production do/do not have a 1:1 association in skeletal muscle. Why add complexity/confusion to a simple issue?2011In: Journal of applied physiology, ISSN 8750-7587, E-ISSN 1522-1601, Vol. 110, no 5, p. 1494-Article in journal (Refereed)
  • 471.
    Sahlin, Kent
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Research group for Mitokondriell funktion och metabolisk kontroll.
    Control of lipid oxidation at the mitochondrial level.2009In: Applied physiology, nutrition, and metabolism = Physiologie appliquée, nutrition et métabolisme, ISSN 1715-5312, Vol. 34, no 3, p. 382-8Article in journal (Refereed)
    Abstract [en]

    The rate of lipid oxidation during exercise is controlled at several sites, and there is a reciprocal dependency between oxidation of lipids and carbohydrates (CHO). It is well known that the proportion of the 2 fuels oxidized is influenced by substrate availability and exercise intensity, but the mechanisms regulating fuel preferences remain unclear. During intense exercise, oxidation of long-chain fatty acids (LCFAs) decreases, and the major control is likely to be at the mitochondrial level. Potential mitochondrial sites for control of lipid oxidation include transport of LCFAs into mitochondrial matrix, beta-oxidation, the tricarboxylic acid cycle, and the electron transport chain (ETC). CHO catabolism may impair lipid oxidation by interfering with the transfer of LCFAs into mitochondria and by competing for mutual cofactors (i.e., nicotinamide adenine dinucleotide and (or) coenzyme A (CoA)). The different effect of energy state on the catabolism of CHO and lipids is likely to be of major importance in explaining the shift in fuel utilization during intensive exercise. Formation of acetyl-CoA from CHO is activated by a low energy state, and will lead to accumulation of products that are inhibitory to lipid oxidation. In contrast, beta-oxidation of LCFAs to acetyl-CoA is not stimulated by a low energy state. Further interaction between CHO and LCFAs may occur by substrate competition for electron carriers at ETC, due to provisions of electrons through different complexes. Feedback inhibition of beta-oxidation by redox state is thought to be an important mechanism for the slowing of lipid oxidation during intensive exercise.

  • 472.
    Sahlin, Kent
    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.
    Fysiologisk forskning åren 1992-20132014In: Från Kungl. Gymnastiska Centralinstitutet till Gymnastik- och idrottshögskolan: en betraktelse av de senaste 25 åren som del av en 200-årig historia / [ed] Suzanne Lundvall, Stockholm: Gymnastik- och idrottshögskolan, GIH , 2014, p. 194-199Chapter in book (Other (popular science, discussion, etc.))
  • 473.
    Sahlin, Kent
    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.
    Mitochondrial function during exercise2016In: Acta Physiologica, ISSN 1748-1708, E-ISSN 1748-1716, Vol. 216, no S707, p. S06-1-Article in journal (Refereed)
  • 474.
    Sahlin, Kent
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Research group for Mitokondriell funktion och metabolisk kontroll.
    Mitokondrier och arbetsfysiologi2013In: Idrottsmedicin, ISSN 2001-3302, no 2, p. 23-25Article in journal (Other academic)
    Abstract [sv]

    Forskning på mitokondriefunktion tillför viktig kunskap om mekanismen till förändringar i träningssvar. Forskning på hur träning med låga glykogennivåer påverkar gener för mitokondrietillväxt är ett exempel på detta.

  • 475.
    Sahlin, Kent
    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.
    Muscle energetics during explosive activities and potential effects of nutrition and training.2014In: Sports Medicine, ISSN 0112-1642, E-ISSN 1179-2035, Vol. 44, no Suppl 2, p. 167-73Article in journal (Refereed)
    Abstract [en]

    The high-energy demand during high-intensity exercise (HIE) necessitates that anaerobic processes cover an extensive part of the adenosine triphosphate (ATP) requirement. Anaerobic energy release results in depletion of phosphocreatine (PCr) and accumulation of lactic acid, which set an upper limit of anaerobic ATP production and thus HIE performance. This report focuses on the effects of training and ergogenic supplements on muscle energetics and HIE performance. Anaerobic capacity (i.e. the amount of ATP that can be produced) is determined by the muscle content of PCr, the buffer capacity and the volume of the contracting muscle mass. HIE training can increase buffer capacity and the contracting muscle mass but has no effect on the concentration of PCr. Dietary supplementation with creatine (Cr), bicarbonate, or beta-alanine has a documented ergogenic effect. Dietary supplementation with Cr increases muscle Cr and PCr and enhances performance, especially during repeated short periods of HIE. The ergogenic effect of Cr is related to an increase in temporal and spatial buffering of ATP and to increased muscle buffer capacity. Bicarbonate loading increases extracellular buffering and can improve performance during HIE by facilitating lactic acid removal from the contracting muscle. Supplementation with beta-alanine increases the content of muscle carnosine, which is an endogenous intracellular buffer. It is clear that performance during HIE can be improved by interventions that increase the capacity of anaerobic ATP production, suggesting that energetic constraints set a limit for performance during HIE.

  • 476.
    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. Karolinska institutet.
    Fernström, Maria
    Karolinska institutet.
    Svensson, Michael
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences. Karolinska institutet.
    Tonkonogi, Michail
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences. Karolinska institutet.
    No evidence of an intracellular lactate shuttle in rat skeletal muscle.2002In: Journal of Physiology, ISSN 0022-3751, E-ISSN 1469-7793, Vol. 541, no Pt 2, p. 569-74Article in journal (Refereed)
    Abstract [en]

    The concerted view is that cytosolic pyruvate is transferred into mitochondria and after oxidative decarboxylation further metabolized in the tricarboxylic acid cycle. Recently this view has been challenged. Based on experimental evidence from rat skeletal muscle it has been concluded that mitochondria predominantly oxidize lactate in vivo and that this constitutes part of an 'intracellular lactate shuttle'. This view appears to be gaining acceptance in the scientific community and due to its conceptual importance, confirmation by independent experiments is required. We have repeated the experiments in mitochondria isolated from rat soleus muscle. Contrary to the previously published findings we cannot find any mitochondrial respiration with lactate. Analysis of lactate dehydrogenase (LDH) by spectrophotometry demonstrated that the activity in the mitochondrial fraction was only 0.7 % of total activity. However, even when external LDH was added to mitochondria, there were no signs of respiration with lactate. In the presence of conditions where lactate is converted to pyruvate (external additions of both LDH and NAD(+)), mitochondrial oxygen consumption increased. Furthermore, we provide theoretical evidence that direct mitochondrial lactate oxidation is energetically unlikely. Based on the present data we conclude that direct mitochondrial lactate oxidation does not occur in skeletal muscle. The presence of an 'intracellular lactate shuttle' can therefore be questioned.

  • 477.
    Sahlin, Kent
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Research group for Mitokondriell funktion och metabolisk kontroll.
    Harris, R C
    Control of lipid oxidation during exercise: role of energy state and mitochondrial factors.2008In: Acta physiologica (Oxford, England), ISSN 1748-1716, Vol. 194, no 4, p. 283-91Article in journal (Refereed)
    Abstract [en]

    Despite considerable progress during recent years our understanding of how lipid oxidation (LOx) is controlled during exercise remains incomplete. This review focuses on the role of mitochondria and energy state in the control of LOx. LOx increases in parallel with increased energy demand up to an exercise intensity of about 50-60% of VO(2max) after which the contribution of lipid decreases. The switch from lipid to carbohydrate (CHO) is of energetic advantage due to the increased ATP/O(2) yield. In the low-intensity domain (<50%VO(2max)) a moderate reduction in energy state will stimulate both LOx and CHO oxidation and relative fuel utilization is mainly controlled by substrate availability and the capacity of the metabolic pathways. In the high-intensity domain (>60%VO(2max)) there is a pronounced decrease in energy state, which will stimulate glycolysis in excess of the substrate requirements of the oxidative processes. This will lead to acidosis, reduced levels of free Coenzyme A (CoASH) and reduced levels of free carnitine. Acidosis and reduced carnitine may limit the carnitine-mediated transfer of long-chain fatty acids (LCFA) into mitochondria and may thus explain the observed reduction in LOx during high-intensity exercise. Another potential mechanism, suggested in this review, is that Acyl-CoA synthetase (ACS), an initial step in LCFA catabolism, functions as a regulator of LOx. ACS activity is suggested to be under control of CoASH and energy state. Furthermore, evidence exists that additional control points exist beyond mitochondrial FA influx. The nature and site of this control remain to be investigated.

  • 478.
    Sahlin, Kent
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Research group for Mitokondriell funktion och metabolisk kontroll.
    Harris, Roger C
    The creatine kinase reaction: a simple reaction with functional complexity.2011In: Amino Acids, ISSN 0939-4451, E-ISSN 1438-2199, Vol. 40, no 5, p. 1363-7Article in journal (Refereed)
    Abstract [en]

    The classical role of PCr is seen as a reservoir of high-energy phosphates defending cellular ATP levels under anaerobic conditions, high rates of energy transfer or rapid fluctuations in energy requirement. Although the high concentration of PCr in glycolytic fast-twitch fibers supports the role of PCr as a buffer of ATP, the primary importance of the creatine kinase (CK) reaction may in fact be to counteract large increases in ADP, which could otherwise inhibit cellular ATPase-mediated systems. A primary role for CK in the maintenance of ADP homeostasis may explain why, in many conditions, there is an inverse relationship between PCr and muscle contractility but not between ATP and muscle contractility. The high rate of ATP hydrolysis during muscle contraction combined with restricted diffusion of ADP suggests that ADP concentration increases transiently during the contraction phase (ADP spikes) and that these are synchronized with the contraction. The presence of CK, structurally bound in close vicinity to the sites of ATP utilization, will reduce the amplitude and duration of the ADP spikes through PCr-mediated phosphotransfer. When PCr is reduced, the efficiency of CK as an ATP buffer will be reduced and the changes in ADP will become more prominent. The presence of ADP spikes is supported by the finding that other processes known to be activated by ADP (i.e. AMP deamination and glycolysis) are stimulated during exercise but not during anoxia, despite the same low global energy state. Breakdown of PCr is driven by increases in ADP above that depicted by the CK equilibrium and the current method to calculate ADPfree from the CK reaction in a contracting muscle is therefore questionable.

  • 479.
    Sahlin, Kent
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Research group for Mitokondriell funktion och metabolisk kontroll.
    Sallstedt, E-K
    Bishop, D
    Tonkonogi, Michail
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences.
    Turning down lipid oxidation during heavy exercise--what is the mechanism?2008In: Journal of physiology and pharmacology : an official journal of the Polish Physiological Society, ISSN 1899-1505, Vol. 59 Suppl 7, p. 19-30Article in journal (Refereed)
    Abstract [en]

    A high potential for lipid oxidation is a sign of metabolic fitness and is important not only for exercise performance but also for health promotion. Despite considerable progress during recent years, our understanding of how lipid oxidation is controlled remains unclear. The rate of lipid oxidation reaches a peak at 50-60% of V(O2 max) after which the contribution of lipids decreases both in relative and absolute terms. In the high-intensity domain (>60% V(O2 max)), there is a pronounced decrease in energy state, which will stimulate the glycolytic rate in excess of the substrate requirements of mitochondrial oxidative processes. Accumulation of glycolytic products will impair lipid oxidation through an interaction with the carnitine-mediated transfer of FA into mitochondria. Another potential site of control is Acyl-CoA synthetase (ACS), which is the initial step in FA catabolism. The activity of ACS may be under control of CoASH and energy state. There is evidence that additional control points exist beyond mitochondrial influx of fatty acids. The electron transport chain (ETC) with associated feed-back control by redox state is one suggested candidate. In this review it is suggested that the control of FA oxidation during heavy exercise is distributed between ACS, CPT1, and ETC.

  • 480.
    Sahlin, Kent
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Research group for Mitokondriell funktion och metabolisk kontroll.
    Seger, Jan
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences.
    Effects of prolonged exercise on the contractile properties of human quadriceps muscle.1995In: European Journal of Applied Physiology and Occupational Physiology, ISSN 0301-5548, E-ISSN 1432-1025, Vol. 71, p. 180-186Article in journal (Refereed)
    Abstract [en]

    The contractile properties of the quadriceps muscle were measured in seven healthy male subjects before, during and after prolonged cycling to exhaustion. Special efforts were made to obtain measurements immediately after exercise. The exercise intensity corresponded to about 75% of estimated maximal O2 uptake and time to exhaustion was mean 85 (SEM 9) min. At the end of the cycling heart rate and perceived exertion for the legs were 94% and 97% of maximal values, respectively. Maximal voluntary isometric force (MVC) had decreased after 5 min of exercise to a mean 91 (SEM 4)% of the pre-exercise value (P < 0.05) and decreased further to a mean 82 (SEM 6) and mean 66 (SEM 5)% after 40-min cycling and at exhaustion, respectively. A new finding was that during recovery reversal of MVC occurred in different phases where the half recovery time of the initial rapid phase was about 2 min. The MVC was a mean 80 (SEM 2)% of the pre-exercise value after 30 min and was not affected by superimposed electrical stimulation. Maximal voluntary concentric and eccentric forces decreased to 74% and 80% of initial values at exhaustion (P < 0.05). The kinetics of isometric contraction expressed as the time between 5% and 50% of tension (rise time) and the time between 95% and 50% of tension (relaxation time) were not significantly affected by the prolonged cycling. The electromechanical delay measured as the time between the first electrical stimulus and 5% of tension decreased from a mean 32 (SEM 1) ms at rest to a mean 26.6 (SEM 0.6) ms at fatigue (P < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

  • 481.
    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.

  • 482.
    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.
    Tonkonogi, Michail
    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.
    Fernström, Maria
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology.
    The leaky mitochondrion.2004In: Physiology News, Vol. 56, p. 27-28Article in journal (Other academic)
  • 483.
    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.
    Hjärtfrekvensmetod för beräkning av syreupptagning under gång- och cykelpendling: ny avhandling2018In: Idrottsmedicin, ISSN 1103-7652, Vol. 7, no 4, p. 29-31Article in journal (Other (popular science, discussion, etc.))
  • 484.
    Salier Eriksson, Jane
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, The Research Unit for Movement, Health and Environment.
    Kan val av transportsätt bidra till bättre folkhälsa och miljö?2013In: Svensk Idrottsmedicin, ISSN 1103-7652, no 2, p. 20-22Article, book review (Other (popular science, discussion, etc.))
  • 485.
    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.
    The heart rate method for estimating oxygen uptake in walking and cycle commuting: Evaluations based on reproducibility and validity studies of the heart rate method and a portable metabolic system2018Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Walking and cycling to work can contribute to population health, but more objective knowledge concerning exercise intensities, oxygen uptake and the metabolic demands of this physical activity is needed for this and other evaluations. To attain this, valid and reliable instruments are a requirement. The focus of this thesis was to evaluate whether the heart rate method can be used for this purpose. It involves establishing the relation between heart rate and oxygen uptake during ergometer cycling in laboratory conditions, and thereafter checking if the same relation exists during cycle or walking commuting in a metropolitan area.

    To accomplish this, a portable metabolic system was tested for validity and reliability in laboratory and field conditions and the reproducibility of the heart rate and oxygen uptake relation in the laboratory was evaluated. Furthermore, the heart rate and oxygen uptake relations during cycle and walking commuting was compared with those attained in the laboratory.

    The first two studies showed that a portable metabolic system is valid during laboratory and sustained field conditions. Studies 3 and 4 showed that the heart rate method with respect to the heart rate-oxygen uptake relationship is reliable on the group level for both walking and cycling commuters during repeated measures in the laboratory. The last two studies showed that applying the heart rate method during cycle commuting leads to valid levels of oxygen uptake on the group level for both males and females. Contrary to that, the measured levels of oxygen uptake in the field during walking commuting were on average 17% higher for males, and 13% higher for females than the values obtained with the heart rate method. For both walking and cycling commuters, the individual spread around the mean values was rather high, creating somewhat wide confidence intervals for the mean values.

    In summary, the heart rate method can be used for cycle commuters during their normal commuting conditions, while for pedestrians it is necessary to take into account that oxygen uptake per heart rate is higher while walking than that estimated from ergometer cycling in the laboratory.

  • 486.
    Salier Eriksson, Jane
    et al.
    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.
    Ekblom Bak, Elin
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology.
    Blom, Victoria
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Sport Psychology research group.
    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.
    Hemmingsson, Erik
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences.
    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.
    Andersson, G
    Wallin, P
    Stenling, A
    Lindwall, M
    Latent profiles of sedentary time, exercise and cardiorespiratory fitness in adults, and the associations with metabolic and percieved health2019Conference paper (Other academic)
  • 487.
    Salier Eriksson, Jane
    et al.
    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.
    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
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology.
    Hemmingsson, Erik
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology.
    Andersson, Gunnar
    HPI Health Profile Institute.
    Wallin, Peter
    HPI Health Profile Institute.
    Ekblom, Örjan
    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.
    Active commuting in Swedish workers between 1998 and 2015 - trends, characteristics and cardiovascular disease risk.2020In: Scandinavian Journal of Medicine and Science in Sports, ISSN 0905-7188, E-ISSN 1600-0838, Vol. 30, no 2Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: Trend analyses of active commuting and potential variations in trends and association with cardiovascular disease (CVD) risk within sub-groups are unknown.

    OBJECTIVES: To a) describe trends in active commuting between 1998 to 2015 and b) to study the association between different amounts of active commuting and the incidence risk of CVD in a large sample of Swedish workers, and analyses of potential variations across sub-groups of socio-demographics, physical activity and BMI.

    METHODS: A total of 318,309 participants (47% women, 18-74 years) who participated in a nationwide occupational health service screening between 1998 and 2015 were included. Commuting habits were self-reported, and data on first-time CVD events were derived from national registers.

    RESULTS: Self-reported passive commuters decreased between 1998 and 2015 (64% to 56%), transferring to an increase in mainly moderate/high-dose active commuters (12% to 19%). Changes were seen in all subgroups. The characteristics and life-style habits of the typical passive and active commuter changed little over the study period. Low- and moderate/high-dose active commuters had significantly decreased risks for a first time CVD during follow-up. This was accentuated in men, middle-aged and in participants with light physical work situations, irregular exercise habits, being overweight/obese and with low fitness.

    CONCLUSION: Increases in active commuting were observed between 1998 and 2015, however still leaving a majority who do not actively commute. As active commuting, regardless dose, is associated with a lower CVD risk, encouraging more people to actively commute may provide an easily accessible and time-efficient possibility to increase physical activity and health in the general population.

    The full text will be freely available from 2020-10-20 01:01
  • 488.
    Salier Eriksson, Jane
    et al.
    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.
    Rosdahl, Hans
    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.
    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.
    Is the heart rate method for estimating oxygen consumption valid in cycle commuting?Manuscript (preprint) (Other academic)
  • 489.
    Salier Eriksson, Jane
    et al.
    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.
    Rosdahl, Hans
    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.
    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.
    Is the heart rate method for estimating oxygen consumption valid in walking commuting?Manuscript (preprint) (Other academic)
  • 490.
    Salier Eriksson, Jane
    et al.
    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.
    Rosdahl, Hans
    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.
    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.
    Relationships between heart rate and oxygen uptake in laboratory conditions and in bicycling commuting2016Conference paper (Refereed)
    Abstract [en]

    Introduction. Measuring the energetic demands of habitual commuter cyclists is essential to create more accurate methods for measuring active commuting so as to be able to objectively determine the impact that cycle commuting can have on population health.

    Heart rate (HR) can be used as an indicator of aerobic processes while commuter cycling as long as the relationship between oxygen uptake (VO2) and HR is established in laboratory conditions. However in the field, environmental aspects might introduce effects of stress that change the relationship. Thus measurements need also to be performed in the field in order to explore the HR-VO2 relationship between the two conditions.

    Methods. Metabolic measurements were performed in the laboratory as well as in the field using 20 habitual commuter cyclists (10 males and 10 females) aged 44 ± 3 yrs. A validated stationary as well as a portable metabolic system was used (Rosdahl et al. 2010; 2016; Salier-Eriksson et al. 2012). A comparison was made between the laboratory and field conditions of the HR-VO2 relationship.

    Results and Discussion. Based on the average heart rate, the measured oxygen uptake was about 2.5 % lower (n.s.) than the expected levels based on the steady state HR-VO2 relationships in the laboratory. Thus, the results indicate that the HR-VO2 relationships in the field were comparable to those measured in the laboratory on a group level. However, relatively large individual differences were found.

    References

    Rosdahl, H., Gullstrand, L., Salier Eriksson, J., Johansson, P. & Schantz, P. 2010. Evaluation of the Oxycon Mobile metabolic system against the Douglas bag method. Eur J Appl Physiol 109 (2):159-71.

    Rosdahl, H., Salier Eriksson, J. & Schantz, P. 2016. Validation of data collected with mobile metabolic measurement systems over time during active commuting. Proceedings of the 21st Annual Congress of The European College of Sport Sciences, Vienna, Austria, 6-8 July (Abstract).  

    Salier Eriksson, J., Rosdahl, H. & Schantz, P. 2012. Validity of the Oxycon Mobile metabolic system under field measuring conditions. Eur J Appl Physiol, 112 (1): 345-355.

     

     

     

  • 491.
    Salier Eriksson, Jane
    et al.
    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.
    Rosdahl, Hans
    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.
    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.
    Validity of the Oxycon Mobile metabolic system under field measuring conditions2012In: European Journal of Applied Physiology, ISSN 1439-6319, E-ISSN 1439-6327, Vol. 112, no 1, p. 345-355Article in journal (Refereed)
    Abstract [en]

    Abstract

    Purpose: It is essential to validate portable metabolic systems, not only in laboratory settings, but also in field measuring conditions, such as prolonged moderate exercise at low temperatures, high humidity and with external wind.

     

    Methods: VO2, VCO2, RER and VE were measured using the Oxycon Mobile (OM), with a windshield, during cycle ergometer exercise: (I) indoors at three submaximal workloads with no wind or with external wind (13–20 m·s-1) from front, side and back; (II) at two submaximal workloads outdoors (12 ± 2oC; 86 ± 7% RH), with and without a system for drying the ambient air around the air sampling tube; and (III) at one workload outdoors for 45 min (5 ± 4oC; 69 ± 16.5% RH). Any physiological drift was checked for with pre- and postmeasurements by the Douglas bag method (DBM).

     

    Results: A minor effect of external wind from behind was noted in RER and VE (-2 and -3%).. The system for drying the ambient air around the gas sampling tube had no effect on the measured levels. A small difference in VCO2 drift between the OM and DBM (1.5 mL·min-2) was noted in the stability test.

     

    Conclusion: Heavy external wind applied from different directions generally does not affect the measurements of the OM. Furthermore, when using a unit for drying the ambient air around the gas sampling tube, the OM can accurately measure VO2, RER and VE   at submaximal workloads for at least45 min under challenging conditions with regard to humidity and temperature.

     

  • 492.
    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.

  • 493. 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.

  • 494.
    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.
    Alfred Nobel och hans okände medarbetare: Alfred Nobel and his unknown coworker2019In: Norrbottens-Kuriren, no 18 december, p. 20-21Article in journal (Other (popular science, discussion, etc.))
    Abstract [en]

    Alfred Nobel is the Swedish inventor of dynamite and the testamentator behind the Nobel Foundation and the Nobel Prizes. The article “Alfred Nobel and his unknown co-worker” is  a translation of the originally in Swedish published article in the daily Swedish newspaper Norrbottens-Kuriren, in December 18, 2019. It elaborates on the issue of which potential persons that Alfred Nobel himself would have toasted in thankfulness for his life and achievements.  Based on Nobel´s testament, and unknown or very sparsely known sources, the great importance of his coworker, the engineer Alarik Liedbeck, protrudes in a new light. Further news in this article is the fact that Liedbeck was a grandchild of the gymnasiarch Per Henrik Ling, who founded the Swedish Ling Gymnastics, including Medical Gymnastics, or what today is known as physiotherapy. Both of them were related to Alfred Nobel through their relative in common; Olof Rudbeck, the older, who discovered the lymph system. Also the grave of Alarik Liedbeck, side by side with Per Henrik Ling, at the shore of Brunnsviken in the Royal National Urban Park in Stockholm, Sweden, sheds light over this unique outdoor burial place which was created by Ling.

  • 495.
    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.
    Along paths converging to Bengt Saltin´s early contributions in exercise physiology2015In: Scandinavian Journal of Medicine and Science in Sports, ISSN 0905-7188, E-ISSN 1600-0838, Vol. 25, no Suppl. 4, p. 7-15Article in journal (Refereed)
    Abstract [en]

    A fascinating chain of events led in 1941 to the formation of the Department of Physiology at the Royal Gymnastic Central Institute (GCI) in Stockholm, Sweden. Erik Hohwü Christensen, from the scientifically advanced Lindhard School in Copenhagen, became its first professor. A central research question for him concerned determining the limiting factors for maximal physical performance in man. This was the academic setting where the sports interested medical student Bengt Saltin was introduced to exercise physiology. In the summer of 1959 he became involved in a study on intermittent versus continuous running. A doctoral project, with Per-Olof Åstrand as his tutor, resulted in 1964 as the thesis ‘Aerobic work capacity and circulation at exercise in man. With special reference to the effect of prolonged exercise and/or heat exposure’. In the decade that followed, Saltin continued along that path. However, he also added a vital research line involving pioneering studies on skeletal muscles in the exercising man, a series of novel studies on the physiological demands in various sports, and studies of the effects of physical training within the general population.

  • 496.
    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.
    Are health effects of cycling underestimated due to inaccurate estimates of the physical activity?2019Conference paper (Other academic)
    Abstract [en]

    The enclosure is a summary of my perspectives as Discussant at the symposium: “Cycling and health in Europe and beyond – explaining and updating the evidence base” at the 10th HEPA Europe Health Enhancing Physical Activity Europe Conference at Southern University of Denmark in Odense, Denmark, August 28-30, 2019. Contributors to the symposium were Drs Adrian Bauman, Sylvia Titze, Niamph Murphy and Pekka Oja.

  • 497.
    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.
    Can nature really affect our health?: A short review of studies2020In: Article in journal (Refereed)
    Abstract [en]

    This is a review which illuminates the chronological order of scientific studies of whether there may be any relationship between nature and morbidity or premature mortality. 

  • 498.
    Schantz, Peter
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, The Research Unit for Movement, Health and Environment.
    City Planning, Physical Activity and Public Health Perspectives in Europe2011In: Proceedings from The 5th Asia-Pacific Conference on Exercise and Sports Science, November 1-4, 2011: Better City Better Life : Through Active Healthy Lifestyles and Sports Science, Shanghai: Shanghai University of Sports, Shanghai, China , 2011, p. 6-7Conference paper (Other academic)
  • 499.
    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.
    Cykelhastighetens betydelse i nyttoanalyser: Mäns och kvinnors cykelhastigheter är högre vid längre avstånd2019Conference paper (Other academic)
    Abstract [sv]

    Bakgrund

    Avstånd, tid och hastighet vid cykling är viktiga ingångsvärden i hälsoekonomiska värderingar, epidemiologiska studier, trafikmodellering och -planering för cykling. Det är därför viktigt att kunna ange så korrekta värden på dem som möjligt. För det krävs studier av samband mellan dessa variabler, och vilka faktorer i övrigt det är som bestämmer hastigheten vid cykling.

    Metodik

    För detta ändamål har en explorativ studiemodell nyttjats. Empiri från 1661 manliga och kvinnliga cykelpendlare i Stor-Stockholm har använts. Deltagarna svarade på enkäter och ritade in sina färdvägar på kartor. Färdvägsavstånden mättes sedan med en kriteriemetod. Var färdvägarna gick har bestämts i förhållande till Stor-Stockholms innerstad och förorter. Självrapporterade data på hur lång tid cykelturen till arbetet tog, ålder, kön, vikt och längd har nyttjats. Multipel regression har använts.

    Resultat

    Stora variationer i cykelhastigheter vid färd till arbetet noterades. Men genom de multipla regressionsanalyserna kunde visas att 56 % av dessa variationer kan förklaras av variationer i ett relativt litet antal variabler. Intressant nog ökade cykelhastigheten ju längre färdvägsavståndet var. Vidare hade män en högre cykelhastighet än kvinnor, men den sjönk med stigande ålder för både män och kvinnor. De som hade en högre kroppsvikter hade högre cykelhastigheter, förutsatt att den högre kroppsvikten inte berodde på högre BMI, och därmed sannolikt mer av fetma. Då sjönk istället cykelhastigheten. Vidare var den högre bland dem som cyklade i ytterstadens förorter än bland dem som cyklade i innerstaden. Studien visade även att de allra flesta som anger sin färdtid i hela minuter och med multiplar av siffran 5 (alltså 5, 10, 15, 20 min, osv.) systematiskt överskattar den tid som det tar för dem att komma till arbetet. Därmed sjunker också deras beräknade cykelhastigheter. Dessa olika faktorers absoluta och relativa betydelse för cykelhastigheten kommer att presenteras vid föredraget.

    Konklusion

    För första gången någonsin redovisas hur ett antal centrala variabler, både enskilt och sammantaget, påverkar cykelhastigheterna för män respektive kvinnor. Därmed finns nu en klart bättre grund för att cyklingens hastigheter ska kunna beskrivas med mer realistiska värden i hälsoekonomiska värderingar, epidemiologiska studier, trafikmodellering och -planering.

  • 500.
    Schantz, Peter
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, The Research Unit for Movement, Health and Environment.
    Cyklistens landskap2013In: Program Transportforum 2013. Linköping 9-10 januari 2013.: Session 30: Planera för aktiv transport – vinn tid, hälsa och miljö, Linköping: Väg- och transportforskningsinstitutet (VTI) , 2013, p. 20-Conference paper (Other academic)
    Abstract [sv]

    Sedan slutet av 1800-talet har cykeln varit så tekniskt utvecklad att den fått roller inom såväl aktiva transporter som rekreation, friluftsliv, motion, träning och tävling. Kraven på cyklistens landskap i dessa olika sammanhang är förvånansvärt lite studerade. Men vi kan utgå från att de skiljer sig åt.  Det finns också ett planeringsbehov för alla dessa syften med cykling. Det är därför viktigt att söka nå kunskap om vilka miljöfaktorer det är som gör att vi upplever färdvägsmiljöer som såväl säkra och trygga samt stimulerande.   

    Färdvägsmiljöer är ofta mycket komplexa. De innehåller många orörliga och rörliga element, samt interaktion mellan dessa. Hur ska man då kunna förstå dessa miljöer, och erhålla säker kunskap om dem och vilka miljövariabler som är kritiska?

    För att nå dithän behöver olika strategier användas. Om man vill erhålla bättre kunskap om vilka miljöfaktorer det är som är kritiska för ovan typer av övergripande bedömningar behöver man kunna renodla betydelsen av enskilda miljövariabler. För detta ändamål har färdvägsmiljöskalan ”The Active Commuting Route Environment Scale” (ACRES) skapats av FoU-gruppen för rörelse, hälsa och miljö vid GIH i Stockholm (www.gih.se/rhm). 

    ACRES är ett instrument som trafikplanerare kan använda för olika former av utvärderingar av färdvägsmiljöer, till exempel för att förstå hur olika segment av färdvägen uppfattas av fotgängare och cyklister, eller för att utvärdera effekten av miljöförbättrande åtgärder.

    Vid föreläsningen beskrivs uppbyggnaden av ACRES samt resultat av studier som bland annat visar att grönska och skönhet i färdvägsmiljön, oberoende av varandra, bidrar till att stimulera cykling vid arbetspendling. Avgaser och trängsel i blandtrafik har motsatt verkan.

     Därutöver beskrivs andra angreppssätt för att nå mer kunskap om hur vi kan skapa färdvägsmiljöer som bidrar till en lust att cykla genom landskapet.

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