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  • 1.
    Alfvén, G
    et al.
    Karolinska institutet.
    Grillner, S
    Karolinska institutet.
    Andersson, Eva
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Laboratory for Biomechanics and Motor Control. Karolinska institutet.
    Children with chronic stress-induced recurrent muscle pain have enhanced startle reaction.2017In: European Journal of Pain, ISSN 1090-3801, E-ISSN 1532-2149, Vol. 21, no 9, p. 1561-1570Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: Children with recurrent pain of negative chronic stress origin from different locations have a characteristic pattern of tender points in the temporal, trapezoid, great pectoral and abdominal muscles. We tested the hypothesis that the startle reaction is activated in these children and that some of the startle-activated muscles are related to the tender point pattern and the recurrent pain.

    METHODS: In children/adolescents, aged 10-17 years, 19 with recurrent psychosomatic pain (PAIN) and 23 controls (CON) we measured and analysed resting activity and acoustic startle response with electromyography (EMG) for the muscles involved in the pattern of tender points and also the lumbar erector spinae.

    RESULTS: The PAIN group showed higher resting activity and higher acoustic startle response values than the CON group for all six muscles together regarding the mean amplitude in the initial 200 ms, and during the burst of activity, and longer burst duration and shorter burst latency. For PAIN versus CON, all separate muscles showed generally higher values of EMG amplitudes and burst durations, and shorter latencies for the burst onset in all measures; with significance or strong trends for several parameters and muscles.

    CONCLUSION: For the first time in children with recurrent psychosomatic pain, increased resting activity and potentiated startle response were demonstrated in the muscles involved in the stress tender point pattern.

    SIGNIFICANCE: This study demonstrates in adolescents how recurrent pain of negative stress origin from the head, stomach, back and chest is related to increased startle reaction and increased muscular tension in these regions. This study contributes to the understanding of the mechanisms underlying the global burden of recurrent pain.

  • 2.
    Andersson, Eva A
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Laboratory for Biomechanics and Motor Control.
    EMG and strength in trunk and hip muscles1997Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The overall aim of this thesis was to study the myouelectric activity of all major muscles involved in the movements and stabilization of the trunk, pelvis and hips during training exercises, postures, motor tasks, maximal strength performance and locomotion. By use of ultra-sound, EMG electrodes could be guided safely and accurately into muscles situated even close to the spinal column, such as psoas, quadratus lumborum and deep parts of erector spinae.

         A task specific variation in activation levels were seen between muscle synergies, as well as between individual muscles within a synergy. Selective engagement of the abdominal muscles could be achieved in trunk flexion sit-ups, that is lifting only the upper trunk from the floor. An even higher activation of abdominal muscles was needed for static stabilization of the trunk and pelvis during hip flexion sit-ups, whereas single leg lifts were performed without involvement of the abdominal muscles. A selective activation of either the iliacus or psoas muscle was observed, for example in certain types of training exercises and in walking and running. Applying bending moments to the spine, resulted in a grading of the muscle activation response according to mechanical advantage, that is highest in the quadratus lumborum in lateral loading and in the superficial erector spinae in ventral loading. An exception was the most forward flexed position in standing where the superficial erector spinae "relaxed" but quadratus lumborum remained active. In general, the level of EMG in maximal efforts was maintained at the same high level irrespective of position in the range of motion, despite a marked variation in strength output. This position-dependency, as well as the strength values as such, varied in a specific way in groups of athletes, related to previous background.

         These data contribute to the understanding of muscle function and motor control of the trunk , pelvis and hips. They are also of relevance when evaluating and designing tests and training programs in rehabilitation and sport contexts as well as for improving biomechanical models of spinal loading.  

  • 3.
    Andersson, Eva A
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Laboratory for Biomechanics and Motor Control.
    EMG and strength in trunk and hip muscles1997In: Svensk Idrottsforskning: Organ för Centrum för Idrottsforskning, ISSN 1103-4629, no 1, p. 48-Article in journal (Other academic)
  • 4.
    Andersson, Helena
    et al.
    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.
    Krustrup, Peter
    Elite football on artificial turf versus natural grass: movement patterns, technical standards, and player impressions.2008In: Journal of Sports Sciences, ISSN 0264-0414, E-ISSN 1466-447X, Vol. 26, no 2, p. 113-22Article in journal (Refereed)
    Abstract [en]

    The aim of the present study was to examine the movement patterns, ball skills, and the impressions of Swedish elite football players during competitive games on artificial turf and natural grass. Time - motion analyses (36 observations) and technical analyses (16 team observations) were performed and 72 male and 21 female players completed a questionnaire. No differences were observed between artificial turf and natural grass in terms of total distance covered (mean 10.19 km, s = 0.19 vs. 10.33 km, s = 0.23), high-intensity running (1.86 km, s = 0.10 vs. 1.87 km, s = 0.14), number of sprints (21, s = 1 vs. 22, s = 2), standing tackles (10, s = 1 vs. 11, s = 1) or headers per game (8, s = 1 vs. 8, s = 1), whereas there were fewer sliding tackles (P < 0.05) on artificial turf than natural grass (2.1, s = 0.5 vs. 4.3, s = 0.6). There were more short passes (218, s = 14 vs. 167, s = 12) and midfield-to-midfield passes (148, s = 11 vs. 107, s = 8) (both P < 0.05) on artificial turf than natural grass. On a scale of 0-10, where 0 = "better than", 5 = "equal to", and 10 = "worse than", the male players reported a negative overall impression (8.3, s = 0.2), poorer ball control (7.3, s = 0.3), and greater physical effort (7.2, s = 0.2) on artificial turf than natural grass. In conclusion, the running activities and technical standard were similar during games on artificial turf and natural grass. However, fewer sliding tackles and more short passes were performed during games on artificial turf. The observed change in playing style could partly explain the male players' negative impression of artificial turf.

  • 5.
    Andersson, Marcus
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences.
    Johansson, Tobias
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences.
    Ergometercykeltest visavi Steptest: Fysiologisk jämförelse mellan två skilda arbeten2010Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

     

    Syfte och frågeställning

    Syftet med studien var att undersöka sambandet mellan hjärtfrekvens (HF), skattad ansträngning samt syreupptag i jämförandet av två arbetsformer; ergometercykel och steplåda. Frågeställning var: hur ser sambandet ut mellan arbetseffekt och HF samt skattad ansträngning för de två arbetena på de givna submaximala effektnivåerna 75 Watt, 125 W samt 175 W. Studien har även för avsikt att jämföra den skattade ansträngningen på ergometercykel kontra den på steplåda vid försök att uppnå maxpuls. Vidare att jämföra den beräknade maximala syreupptagningsförmågan vid Rhyming & Åstrands steptest med den beräknade maximala syreupptagningsförmågan för denna studies modifierade Åstrandstest på ergometercykel. Dessa jämförs sedan med den bestämda maximala syreupptagningsförmågan på ergometercykel.

    Metod

    Datainsamlingen har skett genom att 16 testpersoner, åtta kvinnor och åtta män, utfört två maximala tester, ett On-linetest på ergometercykel Monark Ergomedic 839E där utandningsluften analyserades i blandningskammmare (Oxycon Pro, Jaeger GmbH) och ett på steplåda där enbart HF och skattad ansträngning registrerades med pulsklockan Polar Accurex plus och enligt Borgs RPE-skala, samt två submaximala tester, ett per redskap.

    Resultat

    Vid jämförelse av de två arbetena vid samma givna effekt var testpersonernas HF högre på samtliga submaximala effektnivåer. Testpersonernas upplevda ansträngning, enligt Borgs RPE-skala, var lika på både cykeln o steplådan om testpersonerna skattade 11 eller lägre. Skattade testpersonerna högre än 11 så upplevdes steplådan som mer ansträngande än arbetet på cykeln. Vid sammanställningen av resultaten för testpersonernas olika maximala test på cykel kontra steplåda var skillnaden i HF i medeltal liten.

    Diskussion och konklusion

    Möjlig orsak till att HF och skattad ansträngning var högre för arbetet på steplåda än cykel kan antas vara kraftåtgång. Arbete på steplåda sker vertikalt där acceleration krävs för varje steg upp på steplåda, och där kraft krävs vid inbromsning (excentriskt arbete) vid steg ned från steplåda. Troligtvis är detta mer energikrävande än att upprätthålla en konstant rörelse vid given belastning på cykel. På cykel sker arbetet i en stabilare position samt att energin i cykelns svänghjul hjälper testpersonen att upprätthålla den kraft som krävs för att uppnå given effekt.

     

  • 6.
    Apró, William
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Eva Blomstrand's research group.
    Blomstrand, Eva
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Eva Blomstrand's research group.
    Influence of supplementation with branched-chain amino acids in combination with resistance exercise on p70S6 kinase phosphorylation in resting and exercising human skeletal muscle.2010In: Acta Physiologica, ISSN 1748-1708, E-ISSN 1748-1716, Vol. 200, no 3, p. 237-48Article in journal (Refereed)
    Abstract [en]

    AIM: Skeletal muscle growth is thought to be regulated by the mammalian target of rapamycin (mTOR) pathway, which can be activated by resistance exercise and branched-chain amino acids (BCAA). The major aim of the present study was to distinguish between the influence of resistance exercise and BCAA on key enzymes considered to be involved in the regulation of protein synthesis, including p70(S6) kinase (p70(S6k)). METHODS: Nine healthy subjects (four men and five women) performed unilateral resistance exercise on two occasions separated by 1 month. Subjects were randomly supplied either a mixture of BCAA or flavoured water. Muscle biopsies were taken from both resting and exercising muscle before, after and 1 h after exercise. RESULTS: Phosphorylation of Akt was unaltered by either resistance exercise and/or BCAA supplementation whereas mTOR phosphorylation was enhanced (P<0.05) to a similar extent in both exercising and resting muscle following exercise in the absence (70-90%) and presence of BCAA supplementation (80-130%). Phosphorylation of p70(S6k) was unaffected by resistance exercise alone; however, BCAA intake increased (P<0.05) this phosphorylation in both legs following exercise. In resting muscle, a 5- and 16-fold increase in p70(S6k) was observed immediately after and 1 h after exercise, respectively, as compared to 11- and 30-fold increases in the exercising muscle. Phosphorylation of eukaryotic elongation factor 2 was attenuated 1 h after exercise (P<0.05) in both resting (10-40%) and exercising muscle (30-50%) under both conditions. CONCLUSION: The present findings indicate that resistance exercise and BCAA exert both separate and combined effects on the p70(S6k) phosphorylation in an Akt-independent manner.

  • 7.
    Apró, William
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Eva Blomstrand's research group.
    Wang, Li
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Research group for Mitokondriell funktion och metabolisk kontroll.
    Pontén, Marjan
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Research group for Mitokondriell funktion och metabolisk kontroll.
    Blomstrand, Eva
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Eva Blomstrand's research group.
    Sahlin, Kent
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Research group for Mitokondriell funktion och metabolisk kontroll.
    Resistance exercise induced mTORC1 signaling is not impaired by subsequent endurance exercise in human skeletal muscle.2013In: American Journal of Physiology. Endocrinology and Metabolism, ISSN 0193-1849, E-ISSN 1522-1555, Vol. 305, no 1, p. E22-32Article in journal (Refereed)
    Abstract [en]

    The current dogma is that the muscle adaptation to resistance exercise is blunted when combined with endurance exercise. The suggested mechanism (based on rodent experiments) is that activation of adenosine monophosphate-activated protein kinase (AMPK) during endurance exercise impairs muscle growth through inhibition of the mechanistic target of rapamycin complex 1 (mTORC1). The purpose of this study was to investigate potential interference of endurance training on the signaling pathway of resistance training [mTORC1 phosphorylation of ribosomal protein S6 kinase 1 (S6K1)] in human muscle. Ten healthy and moderately trained male subjects performed on two separate occasions either acute high-intensity and high-volume resistance exercise (leg press, R) or R followed by 30 min of cycling (RE). Muscle biopsies were collected before and 1 and 3 h post resistance exercise. Phosphorylation of mTOR (Ser(2448)) increased 2-fold (P < 0.05) and that of S6K1 (Thr(389)) 14-fold (P < 0.05), with no difference between R and RE. Phosphorylation of eukaryotic elongation factor 2 (eEF2, Thr(56)) was reduced ∼70% during recovery in both trials (P < 0.05). An interesting finding was that phosphorylation of AMPK (Thr(172)) and acetyl-CoA carboxylase (ACC, Ser(79)) decreased ∼30% and ∼50%, respectively, 3 h postexercise (P < 0.05). Proliferator-activated receptor-γ coactivator-1 (PGC-1α) mRNA increased more after RE (6.5-fold) than after R (4-fold) (RE vs. R: P < 0.01) and was the only gene expressed differently between trials. These data show that the signaling of muscle growth through the mTORC1-S6K1 axis after heavy resistance exercise is not inhibited by subsequent endurance exercise. It is also suggested that prior activation of mTORC1 signaling may repress subsequent phosphorylation of AMPK.

  • 8.
    Askling, Carl
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Laboratory for Biomechanics and Motor Control.
    Hamstring muscle strain2008Doctoral thesis, monograph (Other academic)
    Abstract [en]

    Background: Acute hamstring strains are common injuries in different sports. They are often serious, causing long rehabilitation times and a proneness for re-injury. Preliminary observations indicate that the injuries can be of at least two types, one occurring during high-speed running and the other during motions where the hamstring muscles reach extreme lengths.

    Aims: To investigate the possible existence of different types of acute hamstring strains in two specific athletic groups, namely sprinters and dancers, as well as the generality of these findings in other sports.

    Methods: In the first project, 18 sprinters and 15 dancers with acute first time hamstring strains were prospectively included. All subjects were examined, clinically and with magnetic resonance imaging (MRI), on 4 occasions after injury: at day 2-4, 10, 21 and 42. The follow-up period was 2 years. In the second project, 30 subjects from 21 different sports were prospectively included. All subjects were examined clinically and with MRI. The follow-up period lasted until the subjects returned to sport or finished their sport activity due to the injury.

    Results: All sprinters sustained their injuries during competitive high-speed running. In contrast, all dancers encountered their injuries during slow-speed stretching type of exercises. The initial loss of strength and flexibility was significantly greater in sprinters than in dancers. At 42 days after injury, both groups could perform more than 90% of the test values of the uninjured leg. All the sprinters’ injuries were primarily located in biceps femoris long head, whereas the dancers’ injuries were mainly (87%) involving the proximal free tendon of semimembranosus. For the sprinters, involvement of the proximal free tendon, as estimated by MRI, and proximity to the ischial tuberosity, as estimated both by palpation and MRI, were associated with significantly longer time to return to pre-injury level. In the dancers, there were no significant correlations between clinical or MRI parameters and time to return to per-injury level. The time to pre-injury level was significantly longer (median 50 weeks, range 30-76) for the dancers compared to the sprinters (16, 6-50). In the second project, all injuries occurred during movements reaching a position with combined extensive hip flexion and knee extension. They were all located close to the ischial tuberosity and 83% involved the proximal free tendon of semimembranosus. Fourteen subjects (47%) decided to end their sport activity and for the remaining 16 subjects the median time back to sport was 31 (range 9-104) weeks. There were no significant correlations between clinical and MRI parameters and time to return to sport.

    Conclusions: There seems to be a link between the injury situation and the two types of acute hamstring strain in sprinters and dancers with respect to clinical findings, injury location, muscles and tissues involved, and time to return to pre-injury level. Proximity of the injury to the ischial tuberosity, as estimated both by palpation and MRI, is associated with longer recovery time. Also in other sports, an injury situation where the hamstrings reach extensive lengths caused a specific injury to the proximal posterior thigh similar to that described in dancers. Due to the prolonged recovery time associated with this type of injury, correct diagnosis based on history, clinical and MRI investigation, and adequate information to the athletes are essential.

  • 9. Bakkman, Linda
    et al.
    Sahlin, Kent
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Research group for Mitokondriell funktion och metabolisk kontroll.
    Holmberg, H-C
    Tonkonogi, Michail
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences.
    Quantitative and qualitative adaptation of human skeletal muscle mitochondria to hypoxic compared with normoxic training at the same relative work rate.2007In: Acta Physiologica, ISSN 1748-1708, E-ISSN 1748-1716, Vol. 190, no 3, p. 243-51Article in journal (Refereed)
    Abstract [en]

    AIM: To investigate if training during hypoxia (H) improves the adaptation of muscle oxidative function compared with normoxic (N) training performed at the same relative intensity. METHOD: Eight untrained volunteers performed one-legged cycle training during 4 weeks in a low-pressure chamber. One leg was trained under N conditions and the other leg under hypobaric hypoxia (526 mmHg) at the same relative intensity as during N (65% of maximal power output, W(max)). Muscle biopsies were taken from vastus lateralis before and after the training period. Muscle samples were analysed for the activities of oxidative enzymes [citrate synthase (CS) and cytochrome c oxidase (COX)] and mitochondrial respiratory function. RESULTS: W(max) increased with more than 30% over the training period during both N and H. CS activity increased significantly after training during N conditions (+20.8%, P < 0.05) but remained unchanged after H training (+4.5%, ns) with a significant difference between conditions (P < 0.05 H vs. N). COX activity was not significantly changed by training and was not different between exercise conditions [+14.6 (N) vs. -2.3% (H), ns]. Maximal ADP stimulated respiration (state 3) expressed per weight of muscle tended to increase after N (+31.2%, P < 0.08) but not after H training (+3.2%, ns). No changes were found in state four respiration, respiratory control index, P/O ratio, mitochondrial Ca(2+) resistance and apparent Km for oxygen. CONCLUSION: The training-induced increase in muscle oxidative function observed during N was abolished during H. Altitude training may thus be disadvantageous for adaptation of muscle oxidative function.

  • 10. Balsom, Paul D
    et al.
    Gaitanos, G C
    Söderlund, Karin
    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, Björn Ekblom's research group.
    High-intensity exercise and muscle glycogen availability in humans.1999In: Acta Physiologica Scandinavica, ISSN 0001-6772, E-ISSN 1365-201X, Vol. 165, no 4, p. 337-45Article in journal (Refereed)
    Abstract [en]

    This study investigated the effects of muscle glycogen availability on performance and selected physiological and metabolic responses during high-intensity intermittent exercise. Seven male subjects completed a regimen of exercise and dietary intake (48 h) to either lower and keep low (LOW-CHO) or lower and then increase (HIGH-CHO) muscle glycogen stores, on two separate occasions at least a week apart. On each occasion the subjects completed a short-term (<10 min) and prolonged (>30 min) intermittent exercise (IEX) protocol, 24 h apart, which consisted of 6-s bouts of high-intensity exercise performed at 30-s intervals on a cycle ergometer. Glycogen concentration (mean +/- SEM) in m. vastus lateralis before both IEx(short) and IEx(long) was significantly lower following LOW-CHO [180 (14), 181 (17) mmol kg (dw)(-1)] compared with HIGH-CHO [397 (35), 540 (25) mmol kg (dw)(-1)]. In both IEx(short) and IEx(long), significantly less work was performed following LOW-CHO compared with HIGH-CHO. In IEx(long), the number of exercise bouts that could be completed at a pre-determined target exercise intensity increased by 265% from 111 (14) following LOW-CHO to 294 (29) following HIGH-CHO (P < 0.05). At the point of fatigue in IEx(long), glycogen concentration was significantly lower with the LOW-CHO compared with HIGH-CHO [58 (25) vs. 181 (46) mmol kg (dw)(-1), respectively]. The plasma concentrations of adrenaline and nor-adrenaline (in IEx(short) and IEx(long)), and FFAand glycerol (in IEx(long)), increased several-fold above resting values with both experimental conditions. Oxygen uptake during the exercise periods in IEx(long), approached 70% of Vo2max. These results suggest that muscle glycogen availability can affect performance during both short-term and more prolonged high-intensity intermittent exercise and that with repeated exercise periods as short as 6 s, there can be a relatively high aerobic contribution.

  • 11. Balsom, Paul
    et al.
    Seger, Jan
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences.
    Sjödin, Bertil
    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. Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Björn Ekblom's research group.
    Maximal-Intensity Intermittent Exercise: Effect of Recovery Duration1992In: International Journal of Sports Medicine, ISSN 0172-4622, E-ISSN 1439-3964, Vol. 13, no 7, p. 528-533Article in journal (Refereed)
    Abstract [en]

    Seven male subjects performed 15 x 40m sprints, on three occasions, with rest periods of either 120 s (R120), 60 s (R60) or 30 s (R30) between each sprint. Sprint times were recorded with four photo cells placed at 0, 15, 30 and 40 m. The performance data indicated that whereas running speed over the last 10 m of each sprint decreased in all three protocols (after 11 sprints in R120, 7 sprints in R60 and 3 sprints in R30), performance during the initial acceleration period from 0-15 m was only affected with the shortest rest periods increasing from (mean +/- SEM) 2.58 +/- .03 (sprint 1) to 2.78 +/- .04 s (spring 15) (p < .05). Post-exercise blood lactate concentration was not significantly different in R120 (12.1 +/- 1.3 mmol.l-1) and R60 (13.9 +/- 1.2 mmol.l-1), but a higher concentration was found in R30 (17.2 +/- .7 mmol.l-1) (p < .05). After 6 sprints there was no significant difference in blood lactate concentration with the different recovery durations, however, there were significant differences in sprint times at this point, suggesting that blood lactate is a poor predictor of performance during this type of exercise. Although the work bouts could be classified primarily as anaerobic exercise, oxygen uptake measured during rest periods increased to 52, 57 and 66% of maximum oxygen uptake in R120, R60 and R30, respectively. Evidence of adenine nucleotide degradation was provided by plasma hypoxanthine and uric acid concentrations elevated post-exercise in all three protocols. Post-exercise uric acid concentration was not significantly affected by recovery duration.(ABSTRACT TRUNCATED AT 250 WORDS)

  • 12.
    Berg, Ulrika
    et al.
    Institutionen för Kvinnors och Barns Hälsa (KBH), Karolinska Institutet.
    Enqvist, Jonas K
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Björn Ekblom's research group.
    Mattsson, C. Mikael
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Björn Ekblom's research group.
    Carlsson-Skwirut, Christine
    Institutionen för Kvinnors och Barns Hälsa (KBH), Karolinska Institutet.
    Sundberg, Carl-Johan
    Institutionen för Fysiologi och Farmakologi, Karolinska institutet.
    Ekblom, Björn
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Björn Ekblom's research group.
    Bang, Peter
    Institutionen för Kvinnors och Barns Hälsa (KBH), Karolinska Institutet.
    Lack of sex differences in the IGF-IGFBP response to ultra endurance exercise.2008In: Scandinavian Journal of Medicine and Science in Sports, ISSN 0905-7188, E-ISSN 1600-0838, Vol. 18, no 6, p. 706-714Article in journal (Refereed)
    Abstract [en]

    The insulin-like growth factor (IGF)-IGF binding proteins (BP) and the pituitary-gonadal axes were investigated during ultra endurance exercise in 16 endurance-trained athletes (seven women). Median duration of the race was 6.3 days. Although food and drink were ad libitum, energy balance was negative. Blood samples were drawn before (PRE), at the end of (END) and 24 h after (POST24h) the race. Serum concentrations of total IGF-I (t-IGF-I) and free IGF-I (f-IGF-I) decreased by 33 (SD 38)% and 54 (19)%, respectively. The decrease in t-IGF-I appeared to be associated to the total energy deficit during the race. At END, the IGFBP-3 fragmentation and IGFBP-1 were increased but these changes did not predict changes in f-IGF-I. An increase in POST24h IGFBP-2 levels in women was the only sex difference. Testosterone was decreased by 67 (12)% in the men and estradiol became undetectable in the women without any detectable increase in LH and/or FSH. In conclusion ultra endurance exercise results in similar IGF-IGFBP responses in men and women reflecting a catabolic state. IGFBP-2 was the only exception, with increased levels in women after exercise. A concomitant decrease in gonadal hormones was not related to endocrine changes in the IGF-IGFBP axis but may be related to local changes in IGF-I expression.

  • 13.
    Berg, Ulrika
    et al.
    Institutionen för Kvinnors och Barns Hälsa (KBH), Karolinska Institutet.
    Enqvist, Jonas
    Swedish School of Sport and Health Sciences, GIH.
    Mattsson, C. Mikael
    Swedish School of Sport and Health Sciences, GIH.
    Carlsson-Skwirut, Christine
    Institutionen för Kvinnors och Barns Hälsa (KBH), Karolinska Institutet.
    Sundberg, Carl-Johan
    Institutionen för Fysiologi och Farmakologi (FyFa), Karolinska Institutet.
    Ekblom, Björn
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Björn Ekblom's research group.
    Bang, Peter
    Institutionen för Kvinnors och Barns Hälsa (KBH), Karolinska Institutet.
    The IGF- IGFBP system during ultra-endurance exercise in men and women.2007In: Gordon Research Conference – IGF in physiology & disease, Ventura, CA, USA., 2007Conference paper (Other academic)
  • 14. Bishop, David J
    et al.
    Thomas, Claire
    Moore-Morris, Tom
    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.
    Mercier, Jacques
    Sodium bicarbonate ingestion prior to training improves mitochondrial adaptations in rats.2010In: American Journal of Physiology. Endocrinology and Metabolism, ISSN 0193-1849, E-ISSN 1522-1555, Vol. 299, no 2, p. E225-33Article in journal (Refereed)
    Abstract [en]

    We tested the hypothesis that reducing hydrogen ion accumulation during training would result in greater improvements in muscle oxidative capacity and time to exhaustion (TTE). Male Wistar rats were randomly assigned to one of three groups (CON, PLA, and BIC). CON served as a sedentary control, whereas PLA ingested water and BIC ingested sodium bicarbonate 30 min prior to every training session. Training consisted of seven to twelve 2-min intervals performed five times/wk for 5 wk. Following training, TTE was significantly greater in BIC (81.2 +/- 24.7 min) compared with PLA (53.5 +/- 30.4 min), and TTE for both groups was greater than CON (6.5 +/- 2.5 min). Fiber respiration was determined in the soleus (SOL) and extensor digitorum longus (EDL), with either pyruvate (Pyr) or palmitoyl carnitine (PC) as substrates. Compared with CON (14.3 +/- 2.6 nmol O(2).min(-1).mg dry wt(-1)), there was a significantly greater SOL-Pyr state 3 respiration in both PLA (19.6 +/- 3.0 nmol O(2).min(-1).mg dry wt(-1)) and BIC (24.4 +/- 2.8 nmol O(2).min(-1).mg dry wt(-1)), with a significantly greater value in BIC. However, state 3 respiration was significantly lower in the EDL from both trained groups compared with CON. These differences remained significant in the SOL, but not the EDL, when respiration was corrected for citrate synthase activity (an indicator of mitochondrial mass). These novel findings suggest that reducing muscle hydrogen ion accumulation during running training is associated with greater improvements in both mitochondrial mass and mitochondrial respiration in the soleus.

  • 15.
    Bjerkefors, Anna
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Laboratory for Biomechanics and Motor Control.
    Nordlund Ekblom, Maria M
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Laboratory for Biomechanics and Motor Control.
    Josefsson, Karin
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Laboratory for Biomechanics and Motor Control.
    Thorstensson, Alf
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Laboratory for Biomechanics and Motor Control.
    Deep and superficial abdominal muscle activation during trunk stabilization exercises with and without instruction to hollow.2010In: Manual Therapy, ISSN 1356-689X, E-ISSN 1532-2769, Vol. 15, no 5, p. 502-7Article in journal (Refereed)
    Abstract [en]

    The deepest muscle of the human ventro-lateral abdominal wall, the Transversus Abdominis (TrA), has been ascribed a specific role in spine stabilization, which has motivated special core stability exercises and hollowing instruction to specifically involve this muscle. The purpose here was to evaluate the levels of activation of the TrA and the superficial Rectus Abdominis (RA) muscles during five common stabilization exercises performed in supine, bridging and four-point kneeling positions, with and without instruction to hollow, i.e. to continuously pull the lower part of the abdomen towards the spine. Nine habitually active women participated and muscle activity was recorded bilaterally from TrA and RA with intramuscular fine-wire electrodes introduced under the guidance of ultrasound. Results showed that subjects were able to selectively increase the activation of the TrA, isolated from the RA, with the specific instruction to hollow and that side differences in the amplitude of TrA activity, related to the asymmetry of the exercises, remained even after the instruction to hollow. The exercises investigated caused levels of TrA activation from 4 to 43% of that during maximal effort and can thus be used clinically to grade the load on the TrA when designing programs aiming at training that muscle.

  • 16.
    Björkman, Frida
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences.
    Snusets effekter på aeroba processer och energiomsättning under fysiskt arbete2011Independent thesis Advanced level (degree of Master (One Year)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The aim of the present study was to examine the effects of a prolonged cessation from tobacco and nicotine on maximal aerobic power and energy metabolism during submaximal exercise in regular snuff users.

     

    Methods

    23 snuff users (18 men, 5 women) were investigated before and after a >6 week snuff cessation period (SCP). Participants performed a submaximal graded exercise test on cycle ergometer, a maximal running test and a prolonged aerobic endurance test consisting of 60 minutes cycling on 50 % of VO2max. Measurements of oxygen uptake (VO2), ventilation (VE), rate of perceived exertion on Borg´s RPE-scale (RPE), heart rate (HR) and blood pressure (BP) were obtained. Blood samples were drawn for analysis of cotinine, lactate [HLa], blood glucose, and free fatty acids (FFA) at rest and during exercise.

     

    Results

    Submaximal VO2 and energy expenditure were not affected by >6 weeks of withdrawal from snus. VE, respiratory exchange ratio (RER), blood glucose and RPE during submaximal graded exercise test remained unchanged. However, post-SCP a small change was observed in the [HLa] concentration, due to a significantly lower [HLa] at the final stage in the test (7.61 ± 3.01 and 7.18 ± 2.95 mmol/l, respectively, p<0.05). HR and BP were significantly reduced at all submaximal work rates. Mean time to exhaustion during the maximal running test, maximal oxygen uptake (VO2max), maximal HR and [HLa] were almost identical before and after SCP. Significantly lower values of FFA, HR and BP, and a tendency towards lower ventilatory drift during prolonged submaximal exercise were observed post-SCP. No changes were observed on any other measurements during the prolonged exercise test. Other physiological changes were weight gain (1.5 kg ± 1.6 kg, p<0.01) and decreased HR (61 ± 9 beats/min pre-SCP, 55 ± 8 beats/min post-SCP, p<0.05) at rest.

     

    Conclusions

    Oxygen uptake in submaximal aerobic exercise with large muscle groups is not affected by a prolonged cessation from regular snuff dipping. VO2max and maximal aerobic performance is unchanged. Exposure to snus may have some influence on the metabolism during exercise, mainly characterized by lower concentrations of FFA post-SCP.

  • 17.
    Björkman, Frida
    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.
    Edin, Fredrik
    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.
    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 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.
    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.
    Regular oral moist snuff dipping does not impair physical performanceArticle in journal (Refereed)
  • 18.
    Björkman, Frida
    et al.
    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.
    Antiinflammatoriska medel troliga storsäljare i OS2012In: Svensk Idrottsforskning: Organ för Centrum för Idrottsforskning, ISSN 1103-4629, no 2, p. 40-43Article in journal (Other academic)
    Abstract [sv]

    Det är mycket vanligt att idrottare använder antiinflammatoriska läkemedel både för att behandla skador och döva smärta. Hur lämpligt är det att använda preparaten under hård träning och tävling, och vad kan medicineringen ha för konsekvenser?

  • 19.
    Björkman, Frida
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Björn Ekblom's research group.
    Mattsson, C. Mikael
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Björn Ekblom's research group.
    Hur farlig är multisport?2011In: Svensk IdrottsMedicin, ISSN 1103-7652, Vol. 30, no 4, p. 8-11Article in journal (Other academic)
    Abstract [sv]

    Den övervägande delen av deltagarna i större multisporttävlingar drabbas av någon typ av skada som i de flesta fall är lindrig. Men det är ändå ingen tvekan om att multisport kan vara farligt. Det ställs höga krav på medicinsk personal att kunna hantera en mångfald av skador och sjukdomar.

  • 20.
    Blomstrand, Eva
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Eva Blomstrand's research group.
    Ek, Sonja
    Newsholme, Eric A
    Influence of ingesting a solution of branched-chain amino acids on plasma and muscle concentrations of amino acids during prolonged submaximal exercise.1996In: Nutrition (Burbank, Los Angeles County, Calif.), ISSN 0899-9007, E-ISSN 1873-1244, Vol. 12, no 7-8, p. 485-90Article in journal (Refereed)
    Abstract [en]

    On two occasions, seven male endurance-trained cyclists performed sustained exhaustive exercise with reduced muscle glycogen stores. During exercise, the subjects were supplied in random order with an aqueous solution of branched-chain amino acids (BCAA) or flavored water (placebo). Ingestion of BCAA caused the concentration of these amino acids to increase by 135% in the plasma and by 57% in muscle tissue during exercise, whereas in the placebo trial there was no change or a slight decrease in the concentration in plasma and a decrease of 18% in the muscle. The plasma concentration of alanine increased by 48% during exercise when BCAA were ingested, and the increase in the muscle concentration of alanine during exercise was larger (70% versus 31% in the placebo trial), suggesting an increased rate of alanine production. Also, the plasma concentration of arginine increased by 14% during exercise when BCAA were ingested, whereas there was no change during exercise in the placebo trial. There was a smaller decrease in the muscle glutamate concentration during exercise in the BCAA trial (32% versus 47% in the placebo trial; p < 0.05), but, for the remaining amino acids, there was no difference between the BCAA and placebo trials. There was a significant decrease in the muscle glycogen concentration during exercise in the placebo trial, whereas only a small decrease was found in the BCAA trial (28 and 9 mmol/kg wet wt [p < 0.05] in the placebo and BCAA trial, respectively). This might indicate that an increased supply of BCAA has a sparing effect on muscle glycogen degradation during exercise.

  • 21.
    Blomstrand, Eva
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Eva Blomstrand's research group.
    Essén-Gustavsson, Birgitta
    Changes in amino acid concentration in plasma and type I and type II fibres during resistance exercise and recovery in human subjects.2009In: Amino Acids, ISSN 0939-4451, E-ISSN 1438-2199, Vol. 37, no 4, p. 629-36Article in journal (Refereed)
    Abstract [en]

    Eight male subjects performed leg press exercise, 4 x 10 repetitions at 80% of their maximum. Venous blood samples were taken before, during exercise and repeatedly during 2 h of recovery. From four subjects, biopsies were taken from the vastus lateralis muscle prior to, immediately after and following one and 2 h of recovery. Samples were freeze-dried, individual muscle fibres were dissected out and identified as type I or type II. Resistance exercise led to pronounced reductions in the glutamate concentration in both type I (32%) and type II fibres (70%). Alanine concentration was elevated 60-75% in both fibre types and 29% in plasma. Glutamine concentration remained unchanged after exercise; although 2 h later the concentrations in both types of fibres were reduced 30-35%. Two hours after exercise, the plasma levels of glutamate and six of the essential amino acids, including the branched-chain amino acids were reduced 5-30%. The data suggest that glutamate acts as an important intermediate in muscle energy metabolism during resistance exercise, especially in type II fibres.

  • 22.
    Blomstrand, Eva
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Eva Blomstrand's research group.
    Rådegran, Göran
    Saltin, Bengt
    Maximum rate of oxygen uptake by human skeletal muscle in relation to maximal activities of enzymes in the Krebs cycle.1997In: Journal of Physiology, ISSN 0022-3751, E-ISSN 1469-7793, Vol. 501 ( Pt 2), p. 455-60Article in journal (Refereed)
    Abstract [en]

    1. Ten subjects performed incremental exercise up to their maximum work rate with the knee extensors of one leg. Measurements of leg blood flow and femoral arteriovenous differences of oxygen were made in order to be able to calculate oxygen uptake of the leg. 2. The volume of the quadriceps muscle was determined from twenty-one to twenty-five computer tomography section images taken from the patella to the anterior inferior iliac spine of each subject. 3. The maximal activities of three enzymes in the Krebs cycle, citrate synthase, oxoglutarate dehydrogenase and succinate dehydrogenase, were measured in biopsy samples taken from the vastus lateralis muscle. 4. The average rate of oxygen uptake over the quadriceps muscle at maximal work, 353 ml min-1 kg-1, corresponded to a Krebs cycle rate of 4.6 mumol min-1 g-1. This was similar to the maximal activity of oxoglutarate dehydrogenase (5.1 mumol min-1 g-1), whereas the activities of succinate dehydrogenase and citrate synthase averaged 7.2 and 48.0 mumol min-1 g-1, respectively. 5. It is suggested that of these enzymes, only the maximum activity of oxoglutarate dehydrogenase can provide a quantitative measure of the capacity of oxidative metabolism, and it appears that the enzyme is fully activated during one-legged knee extension exercise at the maximal work rate.

  • 23.
    Blomstrand, Eva
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Eva Blomstrand's research group.
    Saltin, Bengt
    BCAA intake affects protein metabolism in muscle after but not during exercise in humans.2001In: American Journal of Physiology. Endocrinology and Metabolism, ISSN 0193-1849, E-ISSN 1522-1555, Vol. 281, no 2, p. E365-74Article in journal (Refereed)
    Abstract [en]

    Branched-chain amino acids (BCAA) or a placebo was given to seven subjects during 1 h of ergometer cycle exercise and a 2-h recovery period. Intake of BCAA did not influence the rate of exchange of the aromatic amino acids, tyrosine and phenylalanine, in the legs during exercise or the increase in their concentration in muscle. The increase was approximately 30% in both conditions. On the other hand, in the recovery period after exercise, a faster decrease in the muscle concentration of aromatic amino acids was found in the BCAA experiment (46% compared with 25% in the placebo condition). There was also a tendency to a smaller release (an average of 32%) of these amino acids from the legs during the 2-h recovery. The results suggest that BCAA have a protein-sparing effect during the recovery after exercise, either that protein synthesis has been stimulated and/or protein degradation has decreased, but the data during exercise are too variable to make any conclusions about the effects during exercise. The effect in the recovery period does not seem to be mediated by insulin.

  • 24.
    Blomstrand, Eva
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Eva Blomstrand's research group.
    Saltin, Bengt
    Effect of muscle glycogen on glucose, lactate and amino acid metabolism during exercise and recovery in human subjects.1999In: Journal of Physiology, ISSN 0022-3751, E-ISSN 1469-7793, Vol. 514 ( Pt 1), p. 293-302Article in journal (Refereed)
    Abstract [en]

    1. Eight subjects performed two-legged exercise, one leg with low and the other with normal muscle glycogen content. The purpose was to study the effect of low initial muscle glycogen content on the metabolic response during 1 h of exercise and 2 h of recovery. This model allows direct comparison of net fluxes of substrates and metabolites over the exercising legs receiving the same arterial inflow. 2. Muscle glycogen breakdown during exercise was 60% lower in the leg with a reduced pre-exercise glycogen concentration and the rate of glucose uptake during exercise was 30% higher. 3. The amount of pyruvate that was oxidized during exercise was calculated to be approximately 450 mmol in the low-glycogen leg and 750 mmol in the normal-glycogen leg, which suggests more fat and amino acid oxidation in the low-glycogen leg. 4. During exercise, there was a significant release of amino acids not metabolized in the muscle, e. g. tyrosine and phenylalanine, only from the low-glycogen leg, suggesting an increased rate of net protein degradation in this leg. 5. The release of tyrosine and phenylalanine from the low-glycogen leg during the exercise period and the change in their muscle concentrations yield a net tyrosine and phenylalanine production rate of 1.4 and 1.5 mmol h-1, respectively. The net rate of protein degradation was then calculated to be 7-12 g h-1. 6. The results suggest that the observed differences in metabolism between the low-glycogen and the normal-glycogen leg are induced by the glycogen level per se, since the legs received the same arterial supply of hormones and substrates.

  • 25.
    Borg, David
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences.
    Granlund, Jesper
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences.
    Skolidrotten ger mer!: Om möjligheten att påverka motoriken positivt med mer fysisk aktivitet på schemat.2009Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Syfte  

    Undersöka om skolbarns motoriska kompetens påverkas av mängden schemalagd fysisk aktivitet. 

    Frågeställningar

    I hur stor utsträckning får skolbarn med fysisk aktivitet schemalagd fem gånger i veckan bättre motorik än de som har schemalagd fysisk aktivitet två gånger i veckan?

    Metod

    Vi har använt oss av ett motoriktest, kallat NyTidstestet, för att testa 111 elever i årskurserna 3-5. Testet består av sexton olika stationer där utförandet av respektive rörelse bedöms på en fyrgradig skala. Testet har genomförts två gånger för att fastställa interreliabiliteten. Det är författarna av studien som agerat bedömare vid motoriktesterna. Motoriktestet har i studien kompletterats av styrketest, enkäter, vägning och mätning. De styrketest som genomförts är upphopp som skall mäta styrkan i underkroppen och arm-hang som skall mäta styrkan i överkroppen. Utöver styrketest har vi även använt oss av enkäter för att få en uppfattning om elevernas aktivitetsgrad utanför skolan och under lektioner i idrott och hälsa. Vägning och mätning har genomförts för att fastställa elevernas BMI. Resultaten ifrån respektive elev och grupp har sedan sammanställts och beräknats i statistik bearbetningsprogrammet SPSS.    

    Resultat

    Elever med schemalagd fysisk aktivitet fem gånger i veckan har bättre motoriska färdigheter än de elever som har det två gånger i veckan. Elevernas aktivitetsgrad utanför skolan påverkar resultatet av motoriktestet. Likaså påverkar elevernas styrka resultatet. När dessa data vägs in i resultatet så finns det ändå stora skillnader i de motoriska färdigheterna mellan de olika skolornas elever. Eleverna som har fysisk aktivitet fem gånger i veckan presterar bäst.

    Slutsats

    Elevernas motoriska kompetens påverkas positivt av antalet timmar schemalagd fysisk aktivitet.

  • 26.
    Borgenvik, Marcus
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Björn Ekblom's research group.
    Nordin, Marie
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Björn Ekblom's research group.
    Mattsson, C. Mikael
    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.
    Blomstrand, Eva
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Eva Blomstrand's research group.
    Ekblom, Björn
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Björn Ekblom's research group.
    Alterations in amino acid concentrations in the plasma and muscle in human subjects during 24 h of simulated adventure racing2012In: European Journal of Applied Physiology, ISSN 1439-6319, E-ISSN 1439-6327, Vol. 112, p. 3679-3688Article in journal (Refereed)
    Abstract [en]

    This investigation was designed to evaluate changes in plasma and muscle levels of free amino acids during an ultra-endurance exercise and following recovery. Nine male ultra-endurance trained athletes participated in a 24-h standardized endurance trial with controlled energy intake. The participants performed 12 sessions of running, kayaking and cycling (4 x each discipline). Blood samples were collected before, during and after exercise, as well as after 28 h of recovery. Muscle biopsies were taken 1 week before the test and after exercise, as well as after 28 h of recovery. During the 24-h exercise, plasma levels of branched-chain (BCAA), essential amino acids (EAA) and glutamine fell 13%, 14% and 19% (P<0.05) respectively, whereas their concentrations in muscle were unaltered. Simultaneously, tyrosine and phenylalanine levels rose 38% and 50% (P<0.05) in the plasma and 66% and 46% (P<0.05) in muscle, respectively. After the 24-h exercise, plasma levels of BCAA were positively correlated with muscle levels of glycogen (r2=0.73, P<0.05), as was the combined concentrations of muscle tyrosine and phenylalanine with plasma creatine kinase (r2=0.55, P<0.05). Following 28-h of recovery, plasma and muscle levels of amino acids had either returned to their initial levels or were elevated. In conclusion, ultra-endurance exercise caused significant changes elevations in plasma and muscle levels of tyrosine and phenylalanine, which suggest an increase in net muscle protein breakdown during exercise. There was a reduction in plasma concentrations of EAA and glutamine during exercise, whereas no changes were detected in their muscle concentration after exercise.

  • 27.
    Boushel, Robert
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology.
    Functional Response Of Mitochondria To Exercise And Extreme Environments2014In: Acta Physiologica, 212(698), S22, 2014, Vol. 212, no 698, p. S22-Conference paper (Refereed)
  • 28.
    Boushel, Robert
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology.
    Ara, I
    Gnaiger, E
    Helge, J W
    González-Alonso, J
    Munck-Andersen, T
    Sondergaard, H
    Damsgaard, R
    van Hall, G
    Saltin, B
    Calbet, J A L
    Low-intensity training increases peak arm VO2 by enhancing both convective and diffusive O2 delivery.2014In: Acta Physiologica, ISSN 1748-1708, E-ISSN 1748-1716, Vol. 211, no 1, p. 122-134Article in journal (Refereed)
    Abstract [en]

    AIM: It is an ongoing discussion the extent to which oxygen delivery and oxygen extraction contribute to an increased muscle oxygen uptake during dynamic exercise. It has been proposed that local muscle factors including the capillary bed and mitochondrial oxidative capacity play a large role in prolonged low-intensity training of a small muscle group when the cardiac output capacity is not directly limiting. The purpose of this study was to investigate the relative roles of circulatory and muscle metabolic mechanisms by which prolonged low-intensity exercise training alters regional muscle VO2 .

    METHODS: In nine healthy volunteers (seven males, two females), haemodynamic and metabolic responses to incremental arm cycling were measured by the Fick method and biopsy of the deltoid and triceps muscles before and after 42 days of skiing for 6 h day(-1) at 60% max heart rate.

    RESULTS: Peak pulmonary VO2 during arm crank was unchanged after training (2.38 ± 0.19 vs. 2.18 ± 0.2 L min(-1) pre-training) yet arm VO2 (1.04 ± 0.08 vs. 0.83 ± 0.1 L min(1) , P < 0.05) and power output (137 ± 9 vs. 114 ± 10 Watts) were increased along with a higher arm blood flow (7.9 ± 0.5 vs. 6.8 ± 0.6 L min(-1) , P < 0.05) and expanded muscle capillary volume (76 ± 7 vs. 62 ± 4 mL, P < 0.05). Muscle O2 diffusion capacity (16.2 ± 1 vs. 12.5 ± 0.9 mL min(-1)  mHg(-1) , P < 0.05) and O2 extraction (68 ± 1 vs. 62 ± 1%, P < 0.05) were enhanced at a similar mean capillary transit time (569 ± 43 vs. 564 ± 31 ms) and P50 (35.8 ± 0.7 vs. 35 ± 0.8), whereas mitochondrial O2 flux capacity was unchanged (147 ± 6 mL kg min(-1) vs. 146 ± 8 mL kg min(-1) ).

    CONCLUSION: The mechanisms underlying the increase in peak arm VO2 with prolonged low-intensity training in previously untrained subjects are an increased convective O2 delivery specifically to the muscles of the arm combined with a larger capillary-muscle surface area that enhance diffusional O2 conductance, with no apparent role of mitochondrial respiratory capacity.

  • 29. Burke, L M
    et al.
    Castell, L M
    Stear, S J
    Rogers, P J
    Blomstrand, Eva
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Eva Blomstrand's research group.
    Gurr, S
    Mitchell, N
    Stephens, F B
    Greenhaff, P L
    BJSM reviews: A-Z of nutritional supplements2009In: British Journal of Sports Medicine, ISSN 0306-3674, E-ISSN 1473-0480, Vol. 43, no 14, p. 1088-90Article in journal (Other academic)
  • 30.
    Cabrera Basurto, Danys Francisco
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences.
    Nordin, Jens Carl Mikael
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences.
    Sambandstudie mellan maximal styrka, effektutveckling och snabbhet2015Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Syfte och frågeställningar: Syftet med studien var att undersöka hos vältränade om det fanns något samband mellan maximal styrka, effektutveckling och snabbhet, dvs tester som till stor del speglar anaerob kapacitet. Syftet var också att undersöka om det här fanns någon skillnad och/eller likhet mellan kvinnor och män.

    (1) Hur ser det eventuella sambandet ut mellan effektutveckling och maximal styrka? (2) Hur ser det eventuella sambandet ut mellan effektutveckling och snabbhet? (3) Hur ser det eventuella sambandet ut mellan maximal styrka och snabbhet? (4) Hur ser det eventuella sambandet ut, på ovanstående frågeställningar, hos kvinnor och män?

    Metod: Metoden var kvantitativ och laborativ, utformad för att undersöka det eventuella sambandet mellan snabbhet, maximal styrka och effektutveckling – Detta testades genom tre olika fysiologiska tester. Testerna genomfördes på en grupp bestående av 10 män (ålder 24,4±2,8 år, kroppsvikt 78,9±9,7 kg och längd 175,6±7,5 cm) och 10 kvinnor (ålder 24,1±1,7 år, kroppsvikt 65±8,0 kg och längd 167±5,7 cm) som var vältränade men hade olika idrottsbakgrund. Målet var att, utifrån den undersökta gruppen, kunna göra uttalanden om en större population. Testerna som genomfördes var 1 RM knäböj (maximal styrka), sprint 5 m, 10 m och 30 m (snabbhet) samt ett Wingate-test (effektutveckling). Med hjälp av statistikprogrammet Statistica 12.0 och beräkningsmetoden Pearson korrelationskoefficient, har rådata från testerna beräknats för att redovisa det eventuella sambandet.

    Resultat: Resultatet visade att det fanns, antingen ett medelstarkt samband eller ett starkt samband mellan alla tre testerna, för hela gruppen. Majoriteten av testerna visade ett starkt samband, endast mellan effektutveckling och snabbhet 5 m och 30 m var det ett medelstarkt samband, inga svaga samband hittades. De starkaste sambanden som hittades, för hela gruppen, var mellan effektutveckling och maximal styrka (r 0,90 i absoluta tal och r 0,78 i relativa tal). Män hade, totalt sett, många fler starka samband mellan de olika testerna än kvinnor, kvinnor hade endast ett enda starkt samband, vilket var mellan effektutveckling och maximal styrka. Män å andra sidan hade, med majoritet (8 av 14), ett starkt samband mellan de olika testerna, de starkaste sambanden hittades mellan effektutveckling och övriga tester.

    Slutsats: Det fanns ett tydligt samband mellan de olika anaeroba kapaciteterna, för hela gruppen. När resultatet redovisas för kvinnor och män enskilt, så var slutsatsen inte densamma – Kvinnor visade både svagare och färre förekommande samband mellan alla kapaciteter än män. 

  • 31. Calbet, J A L
    et al.
    Boushel, Robert
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology.
    Robach, P
    Hellsten, Y
    Saltin, B
    Lundby, C
    Chronic hypoxia increases arterial blood pressure and reduces adenosine and ATP induced vasodilatation in skeletal muscle in healthy humans.2014In: Acta Physiologica, ISSN 1748-1708, E-ISSN 1748-1716, Vol. 211, no 4, p. 574-84Article in journal (Refereed)
    Abstract [en]

    AIMS: To determine the role played by adenosine, ATP and chemoreflex activation on the regulation of vascular conductance in chronic hypoxia.

    METHODS: The vascular conductance response to low and high doses of adenosine and ATP was assessed in ten healthy men. Vasodilators were infused into the femoral artery at sea level and then after 8-12 days of residence at 4559 m above sea level. At sea level, the infusions were carried out while the subjects breathed room air, acute hypoxia (FI O2 = 0.11) and hyperoxia (FI O2 = 1); and at altitude (FI O2 = 0.21 and 1). Skeletal muscle P2Y2 receptor protein expression was determined in muscle biopsies after 4 weeks at 3454 m by Western blot.

    RESULTS: At altitude, mean arterial blood pressure was 13% higher (91 ± 2 vs. 102 ± 3 mmHg, P < 0.05) than at sea level and was unaltered by hyperoxic breathing. Baseline leg vascular conductance was 25% lower at altitude than at sea level (P < 0.05). At altitude, the high doses of adenosine and ATP reduced mean arterial blood pressure by 9-12%, independently of FI O2 . The change in vascular conductance in response to ATP was lower at altitude than at sea level by 24 and 38%, during the low and high ATP doses respectively (P < 0.05), and by 22% during the infusion with high adenosine doses. Hyperoxic breathing did not modify the response to vasodilators at sea level or at altitude. P2Y2 receptor expression remained unchanged with altitude residence.

    CONCLUSIONS: Short-term residence at altitude increases arterial blood pressure and reduces the vasodilatory responses to adenosine and ATP.

  • 32. Calbet, José A L
    et al.
    Losa-Reyna, José
    Peralta, Rafael Torres
    Rasmussen, Peter
    Ponce-González, Jesús Gustavo
    Sheel, A William
    de la Calle-Herrero, Jaime
    Grau, Amelia Guadalupe
    Morales-Alamo, David
    Fuentes, Teresa
    Rodríguez-García, Lorena
    Siebenmann, Christoph
    Boushel, Robert
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Laboratory for Biomechanics and Motor Control.
    Lundby, Carsten
    Limitations to oxygen transport and utilisation during sprint exercise in humans: evidence for a functional reserve in muscle O2 diffusing capacity.2015In: Journal of Physiology, ISSN 0022-3751, E-ISSN 1469-7793, Vol. 593, no 20, p. 4649-4664Article in journal (Refereed)
    Abstract [en]

    KEY POINTS SUMMARY: Severe acute hypoxia reduces sprint performance. Muscle VO2 during sprint exercise in normoxia is not limited by O2 delivery, O2 off-loading from haemoglobin or structure-dependent diffusion constraints in the skeletal muscle of young healthy men. A large functional reserve in muscle O2 diffusing capacity exists and remains available at exhaustion during exercise in normoxia, which is recruited during exercise in hypoxia. During whole-body incremental exercise to exhaustion in severe hypoxia leg VO2 is primarily dependent on convective O2 delivery and less limited by diffusion constraints than previously thought. The kinetics of O2 off-loading from haemoglobin does not limit VO2 peak in hypoxia. Our results indicate that the limitation to VO2 during short sprints resides in mechanisms regulating mitochondrial respiration.

    ABSTRACT: To determine the contribution of convective and diffusive limitations to VO2 peak during exercise in humans oxygen transport and haemodynamics were measured in eleven men (22 ± 2 years) during incremental (IE) and 30-s all-out sprints (Wingate test, WgT), in normoxia (Nx, PI O2 :143 mmHg) and hypoxia (Hyp, PI O2 :73 mmHg). Carboxyhaemoglobin (COHb) was increased to 6-7% before both WgTs to left-shift the oxyhaemoglobin dissociation curve. Leg VO2 was measured by the Fick method, and leg blood flow (BF) with thermodilution and muscle O2 diffusing capacity (DMO2 ) was calculated. In the WgT mean power output, leg BF, leg O2 delivery and leg VO2 were 7, 5, 28 and 23% lower in Hyp than Nx (P < 0.05), however, peak WgT DMO2 was higher in hypoxia (51.5 ± 9.7) than Nx (20.5 ± 3.0 ml min(-1) mmHg(-1) , P < 0.05). Despite a similar PaO2 (33.3 ± 2.4 and 34.1 ± 3.3 mmHg), mean capillary PO2 (16.7 ± 1.2 and 17.1 ± 1.6 mmHg), and peak perfusion during IE and WgT in Hyp, DMO2 and leg VO2 were 12 and 14% higher during WgT than IE in Hyp (both, P < 0.05). DMO2 was apparently insensitive to COHb (COHb: 0.7 vs 7%, in IE Hyp and WgT Hyp). At exhaustion, the Y equilibration index was well above 1.0 in both conditions, reflecting greater convective than diffusive limitation to the O2 transfer both in Nx and Hyp. In conclusion, muscle VO2 during sprint exercise is not limited by O2 delivery, the O2 off-loading from haemoglobin or structure-dependent diffusion constraints in the skeletal muscle. These findings reveal a remarkable functional reserve in muscle O2 diffusing capacity. This article is protected by copyright. All rights reserved.

  • 33.
    Cardinale, Daniele A.
    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.
    Skeletal muscle V̇O2max and mitochondrial p50 measured in-vivo and ex-vivo: effect of hyperoxia in exercise with small and large muscle mass in well-trained individuals2016Conference paper (Other academic)
    Abstract [en]

    In healthy individuals maximal oxygen uptake is limited by cardiac output when exercising with large musclemass, e.g. 2-legged cycling (BIKE), whereas during one-leg knee extension (KE) exercise there is a closermatch between the amounts of O2 delivered to O2 demand. However hyperoxia has been shown to increaseO2 uptake in both work modalities. This study examined the extent to which hyperoxia affects leg oxygentransport, muscle diffusion capacity, mitochondrial oxygen affinity (p50mito) in vivo and ex vivo, and muscleO2 uptake during exercise engaging a large and small muscle mass in well-trained individuals. In this studywe show that light hyperoxia increases O2 uptake at peak incremental exercise (~10%, p< 0.05) in bothBIKE and KE due to an increased O2 delivery (~ 10%, p< 0.05), which in turn is mainly caused by anincreased arterial O2 content (~5%, p< 0.05), and a non-significant increased leg blood flow (~ 5%). Hencehyperoxia decreases mitochondrial O2 affinity as indicated by the higher calculated in vivo mitochondrialp50. Inspired O2 enhanced maximal work rate in BIKE (~6.5%) and in KE (~4.5%).Our data show that in vivo mitop50 is lower than the ex vivo measure in BIKE, whereas in vivo mitop50 issimilar to ex vivo measure in KE. These indicates that mitochondrial OXPHOS capacity was in excess inBIKE, whereas in KE was almost fully utilized in vivo. This study indicated that both during whole body peakexercise as well as during exercise with smaller muscle mass, V̇O2 may not limit O2 diffusion capacity.

  • 34.
    Cardinale, Daniele A
    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. Elite Performance Centre, Bosön.
    Gejl, Kasper D
    University of Southern Denmark.
    Ørtenblad, Niels
    University of Southern Denmark.
    Ekblom, Bjorn
    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.
    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.
    Reliability of maximal mitochondrial oxidative phosphorylation in permeabilized fibers from the vastus lateralis employing high-resolution respirometry.2018In: Physiological Reports, E-ISSN 2051-817X, Vol. 6, no 4, article id e13611Article in journal (Refereed)
    Abstract [en]

    The purpose was to assess the impact of various factors on methodological errors associated with measurement of maximal oxidative phosphorylation (OXPHOS) in human skeletal muscle determined by high-resolution respirometry in saponin-permeabilized fibers. Biopsies were collected from 25 men to assess differences in OXPHOS between two muscle bundles and to assess the correlation between OXPHOS and the wet weight of the muscle bundle. Biopsies from left and right thighs of another five subjects were collected on two occasions to compare limbs and time-points. A single muscle specimen was used to assess effects of the anesthetic carbocaine and the influence of technician. The difference in OXPHOS between two fiber-bundles from the same biopsy exhibited a standard error of measurement (SEM) of 10.5 pmol · s-1  · mg-1 and a coefficient of variation (CV) of 15.2%. The differences between left and right thighs and between two different time-points had SEMs of 9.4 and 15.2 pmol · s-1  · mg-1 and CVs of 23.9% and 33.1%, respectively. The average (±SD) values obtained by two technicians monitoring different bundles of fibers from the same biopsy were 31.3 ± 7.1 and 26.3 ± 8.1 pmol · s-1  · mg-1 . The time that elapsed after collection of the biopsy (up to a least 5 h in preservation medium), wet weight of the bundle (from 0.5 to 4.5 mg) and presence of an anesthetic did not influence OXPHOS. The major source of variation in OXPHOS measurements is the sample preparation. The thigh involved, time-point of collection, size of fiber bundles, and time that elapsed after biopsy had minor or no effect.

  • 35.
    Carlemalm, Anna
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences.
    Kondition ombord- energiomsättning hos Sjöstridsförbandens personal under skyddstjänst.2008Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpStudent thesis
    Abstract [sv]

    Syfte och frågeställningar

    Syftet med detta examensarbete var att göra en inledande studie som ger en första uppfattning av nivån på den aeroba energiomsättningen under skyddstjänst ombord på ett fartyg. Frågeställning: Vilken nivå på den aeroba energiomsättningen når försökspersonerna upp till under skyddstjänstövning?

    Metod

    Tjugotre kadetter som studerar till officerare genomförde förtester i form av submaximalt och maximalt cykeltest samt beep-test för beräkning av maximal syreupptagningsförmåga. Femton av dessa deltog som försökspersoner i en slutövning i skyddstjänst där hjärtfrekvens (Hf) mätningar gjordes och upplevd ansträngning skattades enligt Borgskalan.

    Resultat

    Sex av försökspersonerna uppnådde högst nivåer på den aeroba energiomsättningen under momentet "skrovskadeskydd", sju under momentet "brand 2" och två under "brand 1". Hf varierade mycket mellan momenten och individerna pga. att försökspersonerna hade olika arbetsuppgifter, men det moment som gav högst medel Hf och högst uppnådda Hf var skrovskadeskyddsmomentet. Den skattade ansträngningen enligt Borgskalan upplevdes som mest ansträngande i skrovskadeskyddsmomentet.

    Slutsats

    Under momenten var det flera som under mer än hälften av tiden låg i en pulszon som innebar medelintensivt eller högintensivt arbete, vilket tyder på att det krävs en hög aerob energiomsättning för många av uppgifterna. Trots att uppgifterna fördelades inom grupperna och några fick arbeta hårdare än andra bör den tyngsta uppgiften fungera som minimikrav som samtliga i besättningen måste uppnå. Nivån på ett konditionskrav för sjögående personal går ej att fastställa med denna studie, men värdena som presenteras visar dock att arbetet under längre tid kan ligga på nivåer som kräver en hög aerob energiomsättning.

  • 36.
    Daggfeldt, Karl
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences.
    Muscle Bulging Reduces Muscle Force and Limits the Maximal Effective Muscle Size2006In: Journal of Mechanics in Medicine and Biology, ISSN 0219-5194, Vol. 6, no 3, p. 229-239Article in journal (Refereed)
    Abstract [en]

    A biomechanical model was generated in order to investigate the possible mechanisms behind reductions in muscle performance due to muscle bulging. It was shown that the proportion of fiber force contributing to the total muscle force is reduced with fiber bulging and that the cause of this reduction is due to the intramuscular pressure (IMP) created by the bulging fibers. Moreover, it was established that the amount of IMP generated muscle force reduction is determined by the extent to which muscle thickening restricts muscle fibers from shortening, thereby limiting their power contribution. It was shown that bulging can set a limit to the maximal size a muscle can take without losing force and power producing capability. Possible effects, due to bulging, on maximal muscle force in relation to both muscle length and muscle shortening velocity were also demonstrated by the model.

  • 37.
    Divljak, Gordan
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences.
    Muscular strength and power development to high and low resistance loads in trained individuals.: 8-week intervention2017Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    The full text will be freely available from 2019-06-10 15:30
  • 38.
    Edin, Fredrik
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences.
    Snusets påverkan på balans: skillnad i posturalt svaj hos dagligsnusare före och efter uppehåll från snusbruk2010Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Syfte

    Snusandet har ökat de senaste åren, särskilt bland kvinnor och yngre personer och till flera samhällsgrupper. Rökning har under många år genomgått rigorös forskning och därigenom bevisats vara förenat med ohälsa. Däremot är forskning på snusanvändandets hälsoeffekter eftersatt. En fysiologisk effekt som föreslagits av långvarigt snusande är påverkan på balans (posturalt svaj). Uppsatsens huvudsyfte är att undersöka effekten på balans av ett långvarigt (sex veckor) uppehåll från snus i en grupp av dagligsnusare.

     

    Metod

    I studien genomförde dagligbrukare av snus (n=13) tester av posturalt svaj före och efter sex veckors uppehåll från snus. Undersökningen bestod av sex olika balanspositioner stående på en kraftplatta där amplituden och standardavvikelsen av svajet (tryckcentrumsförflyttning) i sidled (mediolateralt) och framåt-bakåt (anterio-posteriort). En referensgrupp av icke tobaksbrukare (n=15) genomförde samma tester, med minst en dags mellanrum, för att mäta den normala dag-till-dag-variationen i posturalt svaj. Dessutom mättes blodtryck, hjärtfrekvens och kroppsvikt.

     

    Resultat

    Det posturala svajet påverkades i stort inte av att långtidssnusare gjorde ett snusuppehåll på sex veckor. Det fanns inga signifikanta förändringar i amplitud vid någon av de sex positionerna i någon riktning (p-värde mellan 0,09 till 0,92). Standardavvikelsen på rörelsen var signifikant förändrad vid två av tolv mätningar. Dock var de absoluta skillnaderna av samma storleksordning som dagsvariationen vid mätningarna på referensgruppen, och anses därför fysiologiskt obetydliga. Övriga fysiologiska förändringar var att hjärtfrekvensen i vila sänktes med 6±10 slag/minut (p=0,002) och att försökspersonerna gick upp i vikt med 1,7±1,7 kg (p=0,003).

     

    Slutsats

    Ett uppehåll i snusandet på sex veckor hade försumbar effekt på balansen i stillastående, mätt som posturalt svaj, hos personer som snusat dagligen under lång tid. Däremot innebar snusuppehållet en sänkning av hjärtfrekvensen i vila och en ökning av kroppsvikten.

    Abstract Aim The use of Swedish moist snuff has increased in recent years, especially among women and younger people and to several community groups. Smoking has, based on numerous research studies, since long been associated with illness and death. However, research on moist snuff use is neglected. A physiological effect that has been proposed by long-term use of moist snuff is affected balance (postural sway). The main purpose of this paper is to investigate the affect of long-term (six weeks) withdrawal from use of Swedish moist snuff on balance.

     

    Method In the study daily users of snuff (n=13) conducted tests of postural swaying before and after the six week withdrawal from moist snuff. The investigation consisted of six different equilibrium positions standing on a force plate in which the amplitude and standard deviation of sway (center of pressure movement) in the sideways (mediolateral) and forward-backward (anteriorposterior). A reference group of non-tobacco users (n=15) performed the same tests, with at least one day apart, in order to measure the normal day-to-day variation in postural sway. In addition, blood pressure, heart rate and body weight were measured.

     

    Results The postural sway in long-term snuff users was principally not affected by six weeks of withdrawal from snuff. There were no significant changes in amplitude for any of the six positions in any direction (p-values between 0.09-0.92). The standard deviation of movement altered in two out of twelve measurements. However, the absolute difference was of the same magnitude as the day-to-day variance in the measurements of the reference group, and is therefore considered physiologically negligible. Other physiological changes were that the heart rate at rest was decreased by 6±10 bpm (p=0.002) and that the subjects gained weight by 1.7±1.7 kg (p=0.003).

    Conclusion

    A withdrawal from the use of Swedish moist snuff for six weeks had negligible effect on the balance of the stagnation, as measured by the postural swaying, of persons who used Swedish moist snuff daily for a long time. However, a pause from using moist snuff resulted in a reduction in heart rate at rest and an increase in body weight.

  • 39.
    Ekblom Bak, Elin
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology.
    Pettersson, Tobbe
    Lunds universitet.
    Flockhart, Mikael
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology.
    Mattsson, Mikael C
    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.
    F17 – Flygvapenövning 20142015Report (Other academic)
    Abstract [sv]

    På uppdrag av Försvarsmakten genomförde Militärmedicinska forskningsgruppen vid Åstandlaboratoriet vid Gymnastik- och idrottshögskolan Stockholm (GIH), en observationsstudie gällande fysiologisk/medicinsk belastning på 14 flygplatsjägare under en fältövning med beteckningen "F 17 - Flygvapenövning 2014".

    Övningen var indelad i tre etapper, varav den första (c:a 42 tim) och sista (c:a 59 tim) planerades vara mer fysiskt och psykiskt krävande än den mellersta (c:a 114 tim). Registrering av hjärtfrekvens gjordes under hela övningen. Fysiologiska mätningar samt blodprov togs före och efter varje etapp samt efter c:a 12 timmars vila med sedvanliga kost efter övningens avslutande.

    Beräkningar av energiomsättningen för de tre etapperna inklusive viloperioder var c:a 308, 185 respektive 369 kcal/tim, resulterande i totalt c:a 13 000, 21 100 respektive 21 600 kcal per etapp eller totalt c:a 55 700 kcal för hela övningen. De höga fysiska belastningarna i etapp ett och tre är klart högre än tidigare uppmätta data i svenska och utländska militära operationer. Vissa delar av etapp tre resulterade i fysiska belastningar som var på ungefär samma nivå som vid tävlingar i längre uthållighetsidrotter.

    Den höga belastningen resulterade i stora förändringar i fysiologiska parametrar och medicinska markörer. Vissa mätningar av muskelstyrka i armar och ben liksom maximal syreupptagning försämrades. Testosteron sjönk under hela övningen kraftigt. Dessa och andra uppmätta data talar för att fysiska arbetsförmågan – i förlängningen "stridsvärdet" – blev klart försämrat under övningen.

    Mätningen 12 timmar efter övningens avslut visade oväntade resultat. Den subjektiva ansträngningskänslan under standardiserat cykelarbete var klart förbättrat av 12-timmarsvilan efter övningen. Däremot var flertalet medicinska och fysiologiska värden oförändrade jämfört med värden vid testerna 12 timmar tidigare och därmed var de klart lägre än vid testet innan övningens start. Det är uppenbart att återhämtning av stridsvärdet inte kan bedömas subjektivt utan måste avgöras genom reliabla psykologiska och fysiologiska mätningar.

    Undersökningen har gett underlag för fortsatta studier rörande bland annat typer av energitillskott under övning, olika strategier för snabb återhämtning samt försök att finna markörer för individuella reaktionsmönster på "stridsvärde" under långvariga militära operationer.

  • 40.
    Ekblom, Björn
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Björn Ekblom's research group.
    Comments on Point: Counterpoint "Positive effects of intermittent hypoxia (live high:train low) on exercise performance are/are not mediated primarily by augmented red cell volume2005In: Journal of applied physiology, ISSN 8750-7587, E-ISSN 1522-1601, Vol. 99, no 6, p. 2462-Article in journal (Other academic)
  • 41.
    Ekblom, Björn
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Björn Ekblom's research group.
    "In health and in a normoxic environment, VO2 max is/is not limited primarily by cardiac output and locomotor muscle blood flow".: Comment2006In: Journal of applied physiology, ISSN 8750-7587, E-ISSN 1522-1601, Vol. 100, no 4, p. 1416-Article in journal (Other academic)
  • 42.
    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.
    The muscle biopsy technique: Historical and methodological considerations.2017In: Scandinavian Journal of Medicine and Science in Sports, ISSN 0905-7188, E-ISSN 1600-0838, Vol. 27, no 5, p. 458-461Article, review/survey (Refereed)
    Abstract [en]

    The muscle biopsy method is an important tool for clinical and scientific work. In this study, the two most used instruments, the Bergström needle and the Well-Blakesley conchotome, are described. The technique of using those instruments, risks, and other considerations are discussed. Finally, a few consequences and the error of the method for determining muscle fiber type, fiber area, substrates, and metabolites are presented.

  • 43.
    Ekblom, Björn
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Björn Ekblom's research group.
    Mattsson, C. Mikael
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Björn Ekblom's research group.
    Multisport en trend för alltfler2011In: Svensk IdrottsMedicin, ISSN 1103-7652, Vol. 30, no 4, p. 4-7Article in journal (Other academic)
    Abstract [sv]

    En intressant trend i motions- och tävlingsvärlden är att extrema uthållighetsidrotter blir alltfler och dessa får dessutom alltfler utövare. Multisport (engelska Adventure Racing) är en av dessa. Tävlingarna består i allmänhet av löpning, cykling och paddling men ibland läggs också olika fysiska aktiviteter såsom repklättring, inlines och simning in i tävlingen.

  • 44.
    Ekblom, Björn
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Björn Ekblom's research group.
    Mattsson, C. Mikael
    Swedish School of Sport and Health Sciences, GIH.
    Enqvist, Jonas
    Swedish School of Sport and Health Sciences, GIH.
    Multisport - en utmaning i extrem uthållighet2008In: Svensk Idrottsforskning: Organ för Centrum för Idrottsforskning, ISSN 1103-4629, Vol. 17, no 1, p. 18-21Article in journal (Other academic)
  • 45.
    Ekblom, Björn T
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Björn Ekblom's research group.
    Last word on point: counterpoint : Maximal oxygen uptake is/is not limited by a central nervous system governor : Letter to the editor2009In: Journal of applied physiology, ISSN 8750-7587, E-ISSN 1522-1601, Vol. 106, no 1, p. 348-Article in journal (Other academic)
  • 46.
    Ekblom, Örjan
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Björn Ekblom's research group.
    Barn och ungdomars fysiska träning och utveckling2007In: Idrottsledare för barn och ungdom, Stockholm: SISU Idrottsböcker , 2007Chapter in book (Other (popular science, discussion, etc.))
  • 47.
    Ekblom-Bak, Elin
    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.
    Engström, Lars-Magnus
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Forskningsgruppen för pedagogik, idrott och fritidskultur.
    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.
    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.
    LIV 2000: Motionsvanor, fysisk prestationsförmåga och levnadsvanor bland svenska kvinnor och män i åldrarna 20-65 år2011Report (Other (popular science, discussion, etc.))
    Abstract [sv]

    LIV 2000; syfte och frågeställningar

    LIV 90-studien avspeglade för första gången motionsvanor, fysisk status och övergripande hälsostatus i en väl definierad grupp av hela svenska befolkningen. Följaktligen ledde de resultat som LIV 90-studien redovisade till en rad direkta, centrala och övergripande frågor rörande vilka förändringar av det i många avseenden turbulenta 1990-talet som kunde iakttas i den svenska befolkningen vad gäller fysisk aktivitet, levnadsvanor, fysisk kapacitet och hälsotillstånd. Dessutom finns ett intressant perspektiv att jämföra hur den fysiska aktivitetsgraden, prestationsförmågan och hälsorelaterade variabler ser ut i samma ålderskohort med 10 års mellanrum.

    I stort sett sammanfaller undersökta variabler i LIV 2000 av naturliga skäl med den tidigare LIV 90-studiens, men vissa enkätfrågor har med erfarenheter från denna och andra studier, och den forskning som därefter bedrivits, ytterligare preciserats. Det gäller framförallt frågor om den totala fysiska aktiviteten samt frågor som rör inställning till den egna kroppen, den fysiska förmågan liksom frågor om hinder och förutsättningar att ägna sig åt motion. För att säkerställa möjligheterna att studera trender och eventuella förändringar i befolkningen under 1990-talet var designen och genomförandet av LIV 2000 studien i stort sett identisk med LIV 90. Förutom ett samlat tabellverk över de ingående undersökningsvariablerna i LIV 2000-studien (Bilaga B.1)belyser denna rapport mer specifikt följande  områden och frågeställningar:

    I. Omfattning och inriktning av den vuxna befolkningens motionsvanor samt totala fysiska aktivitet. Hur många är motionärer? Hur många är tillräckligt fysiskt aktiva? Motionär och fysiskt aktiv – är det samma  sak?

    II. Fysisk prestationsförmåga; kondition, balans, ben- och bukmuskelstyrka. Hur skiljer det mellan könen och olika åldrar? Hur många har en låg fysisk prestationsförmåga?

    III. Psykisk och fysisk hälsa. Hur är den upplevda hälsan? Och hur är den metabola hälsan? Hur många har en samlad metabol riskbild?

    IV. Förändringar och trender av motionsvanor, total fysisk aktivitet, fysisk prestationsförmåga, livsstil och hälsotillstånd mellan LIV 90 och LIV 2000. Vad hände mellan 1990 och början av 2000-talet? Vilka hälsomässiga riskgrupper finns i befolkningen?

    Innehåll

    1. Bakgrund

    2. Metod och genomförande

    3. Deltagare

    4. Motionsvanor och fysisk aktivitet

    5. Fysisk prestationsförmåga

    6. Hälsa

    7. LIV 90 och LIV 2000 - Vad har hänt över 10 år?

    8. Sammanfattning

    B. 1 Tabellverk

    B. 2 Enkät och testprotokoll

  • 48.
    Eleryd, Mikaela
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences.
    "Att använda fysisk aktivitet som ett hjälpmedel": förändras VO2max hos individer med psykossjukdom?2016Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Syfte och frågeställningar. Syftet med studien var att undersöka om 12 veckors regelbunden fysisk aktivitet, i form av kondition- och styrketräning, gav effekt på syreupptagningsförmåga hos personer med nydebuterad psykossjukdom. Frågeställningar: (1) Kan 12 veckor regelbunden kondition och styrketräning förbättra syreupptagningsförmågan hos personer med nydebuterad psykossjukdom? (2) Finns det någon skillnad mellan könen och syreupptagningsförmåga efter 12 veckors regelbunden fysisk aktivitet?

    Metod. Fit for life är ett forskningssamarbete mellan Karolinska Institutet, Gymnastik- och Idrottshögskolan (GIH) och Stockholms Läns Landsting vars syfte var att använda fysisk aktivitet som ett verktyg för att öka autonomi, kognitiva funktioner och kroppsfunktioner hos personer med nydebuterad psykossjukdom. Datainsamling till denna studie kom att göras utifrån Fit for life. I studien inkluderades 17 personer med nydebuterad psykossjukdom där medelvärdet för gruppens ålder var 29 ± 6,9 (år). Ett förtest utfördes följt av ett eftertest efter en träningsperiod på 12 veckor där deltagarna uppmuntrades att träna 3 gånger i veckan. Under testerna genomfördes ett submaximalt ergometercykeltest och deltagarnas maximala syreupptag uppskattades.

    Resultat. Bortfallet var stort, 52,7%, och det var endast två kvinnor som slutförde studien. Inga signifikanta förbättringar påträffades. En ökning i VO2max skedde hos 41,2 % av deltagarna, en minskning skedde hos 35,2%, samt hos 23,5 % var VO2max oförändrad. Av de som deltog i den organiserade träningen totalt 12 eller fler gånger ökade 57,1% sin VO2max och 42,9 % minskade sin VO2max. Gruppens medelvärde för absolut VO2max ökade med 4,1% och för det relativa VO2max med 6,3%. För de deltagare som tränade 12 gånger eller fler har medelvärdet för absolut VO2max ökat med 7,6% och för relativa VO2max med 7,8%. Dessa resultat är ej signifikanta. En av kvinnorna ökade sitt absoluta VO2max med 27,2% och det relativa VO2max med 21,8%. Den andra kvinnan ökade sitt absoluta VO2max med 8,3 % respektive det relativa med 3,7%. Hos männen ökade 33,3% sitt VO2max och 40% minskade i VO2max, samt hos 26,7% var VO2max oförändrad.

    Slutsats.Underlaget för denna studie var för litet och ingen slutsats kan dras då inga signifikanta förbättringar kunde ses och därmed var det inte möjligt att svara på frågeställningarna. Ett intressant fynd var däremot att när det kommer till personer med nydebuterad psykossjukdom är det viktigt att höja motivationen, stötta dem till regelbunden träning samt minska bortfallet.

  • 49.
    Eliasson, Jörgen
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Eva Blomstrand's research group.
    Elfegoun, Thibault
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences.
    Nilsson, Johnny
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences.
    Köhnke, Rickard
    Ekblom, Björn
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences.
    Blomstrand, Eva
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Eva Blomstrand's research group.
    Maximal lengthening contractions increase p70 S6 kinase phosphorylation in human skeletal muscle in the absence of nutritional supply.2006In: American Journal of Physiology. Endocrinology and Metabolism, ISSN 0193-1849, E-ISSN 1522-1555, Vol. 291, no 6, p. 1197-1205Article in journal (Refereed)
    Abstract [en]

    The aim of this study was to compare the training stimuli of eccentric (lengthening) and concentric (shortening) contractions regarding the effect on signaling enzymes involved in protein synthesis. Ten male subjects performed 4 x 6 maximal eccentric contractions on one leg followed by 4 x 6 maximal concentric contractions on the other. Six additional subjects performed the same protocol, but with maximal concentric and submaximal eccentric exercise of equal force to that of the maximal concentric contractions. Muscle biopsy samples were taken from the vastus lateralis before, immediately after, and 1 and 2 h after exercise in both legs. The average peak force produced during the maximal eccentric exercise was 31% higher than during the maximal concentric exercise, 2,490 (+/-100) vs. 1,894 (+/-108) N (P < 0.05). The maximal eccentric contractions led to two- to eightfold increases in the phosphorylation of p70 S6 kinase (p70(S6k)) and the ribosomal protein S6 that persisted for 2 h into recovery but no significant changes in phosphorylation of Akt or mammalian target of rapamycin (mTOR). Maximal concentric and submaximal eccentric contractions did not induce any significant changes in Akt, mTOR, p70(S6k), or S6 phosphorylation up to 2 h after the exercise. The results indicate that one session of maximal eccentric contractions activates p70(S6k) in human muscle via an Akt-independent pathway and suggest that maximal eccentric contractions are more effective than maximal concentric contractions in stimulating protein synthesis in the absence of a nutritional intake, an effect that may be mediated through a combination of greater tension and stretching of the muscle.

  • 50.
    Emanuelsson, Caroline
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences.
    Strandell, Linnea
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences.
    "Hur gammal skulle du vara om du inte visste hur gammal du är?": En kvantitativ studie om seniorers fysiska aktivitetsvanor2011Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Sammanfattning

    Denna studie handlade främst om fysiska aktivitetsvanor hos seniorer och hur de upplever möjligheterna till fysisk aktivitet inom sin kommun.

     

    Syfte och frågeställningar

    Vårt syfte med studien var att undersöka hur mycket och på vilket sätt seniorer rör på sig i två olika Stockholmskommuner, samt hur de mår. Utöver detta ville vi även ta reda på om de hört talas om VillGott. 

    • Hur ser seniorernas fysiska aktivitetsvanor ut i Huddinge respektive Sollentuna?
    • Hur upplever seniorer i respektive kommuner att möjligheten till fysisk aktivitet är?
    • Har seniorerna i utvalda kommuner hört talas om projektet VillGott?

     

    Metod

    För att samla in data valdes en kvantitativ metod i form av enkät. Insamlingssätten som användes var gruppenkät och hämta-och-lämna-enkät. Enkäten delades ut till 162 seniorer på seniorträffar, seniorcentrum och PRO-aktiviteter inom de båda kommunerna. Enkätsvaren bearbetades i SPSS 19.0.

     

    Resultat

    Studiens resultat visar att 92 % av respondenterna rör på sig minst en gång i veckan och en stor del av dessa rör sig 2-3 dagar i veckan. Större delen (80 %) anser att möjligheterna till fysisk aktivitet är goda. Tre personer av 162 respondenter har hört talas om VillGott.

     

    Slutsats

    Slutsatsen är att en stor andel av seniorerna inom de båda kommunerna utövade fysisk aktivitet och detta borde innebära att möjligheterna till fysisk aktivitet är goda. Beträffande VillGott kan vi konstatera att ryktet ej har spridit sig och att det kanske skulle krävas ytterligare exponering i media eller på annat sätt om de vill att fler ska veta att de finns.

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