Project in brief
Astronauts on long-duration missions may potentially experience compromised aerobic skeletal muscle capacity, facilitating glucose intolerance, and eventually provoking metabolic disorders or cardiovascular diseases, However, it is currently not known if aerobic exercise (AE) training, as requested in flight, would interfere with the effects of resistance exercise (RE) training, aimed at counteracting muscle atrophy. Thus, this project will study ten physically active men age 20-30 yr, subjected to acute concurrent AE and RE (AE+RE), or RE only. The knee extensors of either limb will perform ~45 min continuous AE, using a 1-legged cycle ergometer. Six hours later, RE will be employed using YoYo™ technology (4 sets of 7 maximal coupled concentric and eccentric actions; leg press and knee extension) for both limbs. Muscle biopsies are obtained from m. vastus lateralis immediately before, 15 min after and 3 hrs after RE to establish whether AE+RE induces different gene expression (microarray analysis) pattern (impression) than RE only. Gene expression arrays will also identify specific gene network differently activated with the two exercise regimes. Pathways, i.e., factors involved in regulation of protein balance (the AKT/mTOR pathway, MuRF and atrogin), metabolic pathways, (the PGC1-α, PPAR, TFAM) and vascular supply (VEGF and angiopoietins), are analyzed using quantitative PCR analysis (mRNA), and Western blot and commercial sandwich ELISA kit (protein quantification).
This study will disclose whether concurrent AE and RE training using YoYo™ technology will induce favorable skeletal muscle molecular adaptations that could blunt potential health threatening effects experienced by space travelers or caused by muscle disuse. Equally important, this project will advance exercise hardware and protocols for terrestrial applications and for astronauts on extended missions in Orbit.
Our research focus is to explore and describe mechanisms and stimuli behind skeletal muscle adaptations to different types of exercise, and to identify potential responders and non-responders to exercise training.
Research in the field
- Norrbom J, Sällstedt E-K, Fischer H, Sundberg CJ, Rundqvist H, Gustafsson T. Alternative splice variant PGC-1α-b is strongly induced by exercise in human skeletal muscle. Am J Physiol Endocrinol Metab 301:E1092-1098, 2011.
- Keller P, Vollaard N, Gustafsson T, Gallagher IJ, Sundberg CJ, Rankinen T, Britton SL, Bouchard C, Koch LG, Timmons J. A transcriptional map of the impact of endurance exercise training on skeletal muscle phenotype. J Appl Physiol 110:46-59, 2011.
- Gustafsson, T, Osterlund T, Flanagan JN, von Waldén F, Trappe TA, Linnehan RM, Tesch, PA. The effects of three days unloading on gene expression that control muscle size in man. J Appl Physiol 109:721-727, 2010.
- Gustafsson, T, Rundqvist H, Norrbom J, Rullman E, Jansson, E, Sundberg CJ. The influence of physical training on the angiopoietin and VEGF-A systems in human skeletal muscle. J Appl Physiol 103:1012-1020, 2007.