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Blomstrand, E. & Apro, W. (2018). Det viktigaste du behöver veta om protein och träning. Idrottsforskning.se, Article ID 30 maj.
Open this publication in new window or tab >>Det viktigaste du behöver veta om protein och träning
2018 (Swedish)In: Idrottsforskning.se, ISSN 2002-3944, article id 30 majArticle in journal (Other (popular science, discussion, etc.)) Published
Place, publisher, year, edition, pages
Stockholm: Centrum för idrottsforskning, CIF, 2018
National Category
Sport and Fitness Sciences
Research subject
Medicine/Technology
Identifiers
urn:nbn:se:gih:diva-5443 (URN)
Available from: 2018-10-16 Created: 2018-10-16 Last updated: 2018-10-17Bibliographically approved
Rundqvist, H. C., Esbjörnsson, M., Rooyackers, O., Apro, W., Moberg, M., Österlund, T. & Jansson, E. (2016). Amino Acid Transport after Sprint Exercise and Oral Amino Acids: 90 Board #6 June 1, 9. In: Medicine & Science in Sports & Exercise: Volume 48(5S) Supplement 1, May 2016, p 5: . Paper presented at American College of Sports Medicine (ACSM) 63rd Annual Meeting, May 31-June 4 2016, Boston (pp. 5). , 48(5 Suppl 1)
Open this publication in new window or tab >>Amino Acid Transport after Sprint Exercise and Oral Amino Acids: 90 Board #6 June 1, 9
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2016 (English)In: Medicine & Science in Sports & Exercise: Volume 48(5S) Supplement 1, May 2016, p 5, 2016, Vol. 48, no 5 Suppl 1, p. 5-Conference paper, Published paper (Other academic)
Abstract [en]

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

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

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

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

National Category
Sport and Fitness Sciences
Research subject
Medicine/Technology
Identifiers
urn:nbn:se:gih:diva-4566 (URN)10.1249/01.mss.0000485021.31770.d3 (DOI)27584180 (PubMedID)
Conference
American College of Sports Medicine (ACSM) 63rd Annual Meeting, May 31-June 4 2016, Boston
Available from: 2016-09-15 Created: 2016-09-15 Last updated: 2016-09-16Bibliographically approved
Apró, W., Moberg, M., Holmberg, H.-C. & Blomstrand, E. (2016). Amino Acid-induced S6K1 Activity In Human Skeletal Muscle Is Mediated By Increased mTor/Rheb Interaction: 128 June 1, 11: 15 AM - 11: 30 AM.. In: Medicine And Science In Sports And Exercise 2016 May; Vol. 48 (5S Suppl 1), pp. 17.: (pp. 17-17). , 48(5S Suppl 1)
Open this publication in new window or tab >>Amino Acid-induced S6K1 Activity In Human Skeletal Muscle Is Mediated By Increased mTor/Rheb Interaction: 128 June 1, 11: 15 AM - 11: 30 AM.
2016 (English)In: Medicine And Science In Sports And Exercise 2016 May; Vol. 48 (5S Suppl 1), pp. 17., 2016, Vol. 48, no 5S Suppl 1, p. 17-17Conference paper, Published paper (Refereed)
Abstract [en]

Cell culture studies have shown that amino acids activate mTORC1 signaling by increasing the interaction between mTOR and its essential activator Rheb. However, the existence of this mechanism in human skeletal muscle remains to be determined.

PURPOSE: To determine if increased mTORC1 signaling in response to amino acids in human skeletal muscle is due to an increased interaction between mTOR and Rheb.

METHODS: Eight well trained men performed resistance exercise on two separate occasions. In connection with the exercise, subjects were supplemented with flavored water (Pla) and essential amino acids (EAA) in a double-blind, randomized cross-over design. Muscle biopsies were taken in the vastus lateralis muscle before, immediately after and 90 and 180 min post exercise. Activity of the mTORC1 pathway was assessed by a radiolabeled in-vitro kinase assay for its immediate downstream target S6K1. Protein-protein interactions were determined by western blot following co-immunoprecipitation of mTOR with Rheb. Co-immunoprecipitation was performed on pooled muscle samples from three of the eight subjects.

RESULTS: Activity of S6K1 remained unchanged immediately after exercise in both trials. However, at 90 min post exercise, S6K1 activity increased by approximately 2- and 8-fold (p<0.05) from baseline the Pla and EAA trials, respectively. At the 180 min time point, S6K1 activity remained elevated in both trials being approx. 3-fold higher in the Pla trial and 5-fold higher (p<0.05) in the EAA trial. The fold-change in mTOR and Rheb interaction largely resembled the activity pattern of S6K1 in both trials; in the Pla trial the fold-change was 0.9, 1.3 and 1.4 while in the EAA trial the fold-change was 1.6, 2.9 and 1.9 immediately after, 90 min after and 180 min after exercise, respectively.

CONCLUSIONS: The large increase in S6K1 activity following EAA intake appears to be mediated by an increased interaction between mTOR and its proximal activator Rheb. This is the first time this mechanism has been demonstrated in human skeletal muscle.

National Category
Sport and Fitness Sciences
Research subject
Medicine/Technology
Identifiers
urn:nbn:se:gih:diva-4514 (URN)
Available from: 2016-08-05 Created: 2016-08-05 Last updated: 2016-08-08Bibliographically approved
Kazior, Z., Willis, S. J., Moberg, M., Apró, W., Calbet, J. A., Holmberg, H.-C. & Blomstrand, E. (2016). Endurance Exercise Enhances the Effect of Strength Training on Muscle Fiber Size and Protein Expression of Akt and mTOR.. PLoS ONE, 11(2), Article ID e0149082.
Open this publication in new window or tab >>Endurance Exercise Enhances the Effect of Strength Training on Muscle Fiber Size and Protein Expression of Akt and mTOR.
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2016 (English)In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 11, no 2, article id e0149082Article in journal (Refereed) Published
Abstract [en]

Reports concerning the effect of endurance exercise on the anabolic response to strength training have been contradictory. This study re-investigated this issue, focusing on training effects on indicators of protein synthesis and degradation. Two groups of male subjects performed 7 weeks of resistance exercise alone (R; n = 7) or in combination with preceding endurance exercise, including both continuous and interval cycling (ER; n = 9). Muscle biopsies were taken before and after the training period. Similar increases in leg-press 1 repetition maximum (30%; P<0.05) were observed in both groups, whereas maximal oxygen uptake was elevated (8%; P<0.05) only in the ER group. The ER training enlarged the areas of both type I and type II fibers, whereas the R protocol increased only the type II fibers. The mean fiber area increased by 28% (P<0.05) in the ER group, whereas no significant increase was observed in the R group. Moreover, expression of Akt and mTOR protein was enhanced in the ER group, whereas only the level of mTOR was elevated following R training. Training-induced alterations in the levels of both Akt and mTOR protein were correlated to changes in type I fiber area (r = 0.55-0.61, P<0.05), as well as mean fiber area (r = 0.55-0.61, P<0.05), reflecting the important role played by these proteins in connection with muscle hypertrophy. Both training regimes reduced the level of MAFbx protein (P<0.05) and tended to elevate that of MuRF-1. The present findings indicate that the larger hypertrophy observed in the ER group is due more to pronounced stimulation of anabolic rather than inhibition of catabolic processes.

National Category
Sport and Fitness Sciences
Research subject
Medicine/Technology
Identifiers
urn:nbn:se:gih:diva-4363 (URN)10.1371/journal.pone.0149082 (DOI)000371218400061 ()26885978 (PubMedID)
Available from: 2016-02-24 Created: 2016-02-24 Last updated: 2017-11-30Bibliographically approved
Apro, W., Moberg, M., Ekblom, B., Holmberg, H.-C. & Blomstrand, E. (2016). High intensity interval cycling performed prior to resistance exercise stimulates autophagy signaling. In: Conference program & abstracts: . Paper presented at 2016 APS Intersociety Meeting. The Integrative Biology of Exercise VII. November 2-4 2016, Phoenix, Arizona. (pp. 84-84).
Open this publication in new window or tab >>High intensity interval cycling performed prior to resistance exercise stimulates autophagy signaling
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2016 (English)In: Conference program & abstracts, 2016, p. 84-84Conference paper, Oral presentation with published abstract (Other academic)
National Category
Sport and Fitness Sciences
Research subject
Medicine/Technology
Identifiers
urn:nbn:se:gih:diva-4631 (URN)
Conference
2016 APS Intersociety Meeting. The Integrative Biology of Exercise VII. November 2-4 2016, Phoenix, Arizona.
Available from: 2016-11-08 Created: 2016-11-08 Last updated: 2017-03-31
Samuelsson, H., Moberg, M., Apró, W., Ekblom, B. & Blomstrand, E. (2016). Intake of branched-chain or essential amino acids attenuates the elevation in muscle levels of PGC-1α4 mRNA caused by resistance exercise.. American Journal of Physiology. Endocrinology and Metabolism, 311(1), E246-E251
Open this publication in new window or tab >>Intake of branched-chain or essential amino acids attenuates the elevation in muscle levels of PGC-1α4 mRNA caused by resistance exercise.
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2016 (English)In: American Journal of Physiology. Endocrinology and Metabolism, ISSN 0193-1849, E-ISSN 1522-1555, Vol. 311, no 1, p. E246-E251Article in journal (Refereed) Published
Abstract [en]

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

National Category
Sport and Fitness Sciences
Research subject
Medicine/Technology
Identifiers
urn:nbn:se:gih:diva-4460 (URN)10.1152/ajpendo.00154.2016 (DOI)000380372000020 ()27245337 (PubMedID)
External cooperation:
Available from: 2016-06-15 Created: 2016-06-15 Last updated: 2017-11-28Bibliographically approved
Apró, W., Moberg, M., Hamilton, D. L., Ekblom, B., Rooyackers, O., Holmberg, H.-C. & Blomstrand, E. (2015). Leucine does not affect mechanistic target of rapamycin complex 1 assembly but is required for maximal ribosomal protein s6 kinase 1 activity in human skeletal muscle following resistance exercise.. The FASEB Journal, 29(10), 4358-4373
Open this publication in new window or tab >>Leucine does not affect mechanistic target of rapamycin complex 1 assembly but is required for maximal ribosomal protein s6 kinase 1 activity in human skeletal muscle following resistance exercise.
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2015 (English)In: The FASEB Journal, ISSN 0892-6638, E-ISSN 1530-6860, Vol. 29, no 10, p. 4358-4373Article in journal (Refereed) Published
Abstract [en]

We examined how the stimulatory effect of leucine on the mechanistic target of rapamycin complex 1 (mTORC1) pathway is affected by the presence of the remaining essential amino acids. Nine male subjects performed resistance exercise on 4 occasions and were randomly supplied essential amino acids (EAAs) with or without leucine (EAA-Leu), leucine alone, or flavored water (placebo; control). Muscle biopsies were taken from the vastus lateralis before and 60 and 90 min after exercise. Biopsies were analyzed for protein phosphorylation, kinase activity, protein-protein interactions, amino acid concentrations, and tracer incorporation. Leucine alone stimulated ribosomal protein s6 kinase 1 (S6K1) phosphorylation ∼280% more than placebo and EAA-Leu after exercise. Moreover, this response was enhanced by 60-75% after intake of EAAs compared with that of leucine alone (P < 0.05). Kinase activity of S6K1 reflected that of S6K1 phosphorylation; 60 min after exercise, the activity was elevated 3.3- and 4.2-fold with intake of leucine alone and with EAAs, respectively (P < 0.05). The interaction between mammalian target of rapamycin and regulatory-associated protein of mammalian target of rapamycin was unaltered in response to both resistance exercise and amino acid provision. Leucine alone stimulates mTORC1 signaling, although this response is enhanced by other EAA and does not appear to be caused by alterations in mTORC1 assembly.-Apró, W., Moberg, M., Hamilton, D. L., Ekblom, B., Rooyackers, O., Holmberg, H.-C., Blomstrand, E. Leucine does not affect mechanistic target of rapamycin complex 1 assembly but is required for maximal ribosomal protein s6 kinase 1 activity in human skeletal muscle following resistance exercise.

National Category
Medical and Health Sciences
Research subject
Medicine/Technology
Identifiers
urn:nbn:se:gih:diva-4132 (URN)10.1096/fj.15-273474 (DOI)000361367300024 ()26169935 (PubMedID)
Available from: 2015-09-14 Created: 2015-09-14 Last updated: 2017-12-04Bibliographically approved
Apró, W., Moberg, M., Hamilton, L., Ekblom, B., van Hall, G., Holmberg, H. & Blomstrand, E. (2015). Resistance exercise induced S6K1 kinase activity is not inhibited in human skeletal muscle despite prior activation of AMPK by high intensity interval cycling.. American Journal of Physiology. Endocrinology and Metabolism, 308(6), E470-E481
Open this publication in new window or tab >>Resistance exercise induced S6K1 kinase activity is not inhibited in human skeletal muscle despite prior activation of AMPK by high intensity interval cycling.
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2015 (English)In: American Journal of Physiology. Endocrinology and Metabolism, ISSN 0193-1849, E-ISSN 1522-1555, Vol. 308, no 6, p. E470-E481Article in journal (Refereed) Published
Abstract [en]

Combining endurance and strength training in the same session has been reported to reduce the anabolic response to the latter form of exercise. The underlying mechanism, based primarily on results from rodent muscle, is proposed to involve AMPK-dependent inhibition of mTORC1 signaling. This hypothesis was tested in eight trained male subjects who in a randomized order performed either resistance exercise only (R) or interval cycling followed by resistance exercise (ER). Biopsies taken from the vastus lateralis before and after endurance exercise and repeatedly after resistance exercise were assessed for glycogen content, kinase activity, protein phosphorylation and gene expression. Mixed muscle fractional synthetic rate was measured at rest and during 3h of recovery using the stable isotope technique. In ER, AMPK activity was elevated immediately after both endurance and resistance exercise (~90%, P<0.05) but was unchanged in R. Thr389 phosphorylation of S6K1 was increased several-fold immediately after exercise (P<0.05) in both trials and increased further throughout recovery. After 90 and 180 min recovery, S6K1 activity was elevated (~55% and ~110%, respectively, P<0.05) and eEF2 phosphorylation was reduced (~55%, P<0.05) with no difference between trials. In contrast, markers for protein catabolism were differently influenced by the two modes of exercise; ER induced a significant increase in gene and protein expression of MuRF1 (P<0.05), which was not observed following R exercise only. In conclusion, cycling-induced elevation in AMPK activity does not inhibit mTORC1 signaling after subsequent resistance exercise, but may instead interfere with the hypertrophic response by influencing key components in protein breakdown.

National Category
Medical and Health Sciences
Research subject
Medicine/Technology
Identifiers
urn:nbn:se:gih:diva-3322 (URN)10.1152/ajpendo.00486.2014 (DOI)
Note

At the time of William Apró's dissertation the publication was a manuscript.

Available from: 2014-05-27 Created: 2014-05-27 Last updated: 2017-12-05Bibliographically approved
Moberg, M., Apró, W., Ohlsson, I., Pontén, M., Villanueva, A., Ekblom, B. & Blomstrand, E. (2014). Absence of leucine in an essential amino acid supplement reduces activation of mTORC1 signalling following resistance exercise in young females.. Applied Physiology, Nutrition and Metabolism, 39(2), 183-94
Open this publication in new window or tab >>Absence of leucine in an essential amino acid supplement reduces activation of mTORC1 signalling following resistance exercise in young females.
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2014 (English)In: Applied Physiology, Nutrition and Metabolism, ISSN 1715-5312, E-ISSN 1715-5320, Vol. 39, no 2, p. 183-94Article in journal (Refereed) Published
Abstract [en]

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

National Category
Physiology
Research subject
Medicine/Technology
Identifiers
urn:nbn:se:gih:diva-3273 (URN)10.1139/apnm-2013-0244 (DOI)24476474 (PubMedID)
Available from: 2014-03-31 Created: 2014-03-31 Last updated: 2018-01-11Bibliographically approved
Moberg, M., Apró, W., Ekblom, B. & Blomstrand, E. (2014). High-intensity cycling performed prior to resistance exercise does not influence mTORC1-signaling and the rate of muscle protein synthesis in the triceps brachii. In: : . Paper presented at 19th annual Congress of the European College of Sport Science, 2-5 July 2014, Amsterdam The Netherlands.
Open this publication in new window or tab >>High-intensity cycling performed prior to resistance exercise does not influence mTORC1-signaling and the rate of muscle protein synthesis in the triceps brachii
2014 (English)Conference paper, Oral presentation with published abstract (Other academic)
Abstract [en]

Introduction

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

 

Methods

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

 

Results

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

 

Conclusion

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

 

 

References

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

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

National Category
Natural Sciences Medical and Health Sciences
Research subject
Medicine/Technology
Identifiers
urn:nbn:se:gih:diva-3647 (URN)
Conference
19th annual Congress of the European College of Sport Science, 2-5 July 2014, Amsterdam The Netherlands
Funder
Swedish National Centre for Research in Sports
Available from: 2015-01-08 Created: 2015-01-08 Last updated: 2017-03-31Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0003-1942-2919

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