Exercise duration-matched interval and continuous sprint cycling induce similar increases in AMPK phosphorylation, PGC-1α and VEGF mRNA expression in trained individuals

• Published in: European journal of applied physiology Vol. 116; no. 8; pp. 1445 - 1454
• Main Authors: Taylor, Conor W., Ingham, Stephen A., Hunt, Julie E. A., Martin, Neil R. W., Pringle, Jamie S. M., Ferguson, Richard A.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.08.2016
• Subjects: Adult; AMP-Activated Protein Kinases - metabolism; Angiogenic Proteins - metabolism; Bicycling - physiology; Biomedical and Life Sciences; Biomedicine; Cross-Over Studies; Human Physiology; Humans; Male; Mitochondria - physiology; Neovascularization, Physiologic - physiology; Occupational Medicine/Industrial Medicine; Organelle Biogenesis; Original; Original Article; Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha - metabolism; Phosphorylation; Physical Exertion - physiology; Quadriceps Muscle - blood supply; Quadriceps Muscle - physiology; Sports Medicine; Treatment Outcome; Vascular Endothelial Growth Factor A - genetics; Vascular Endothelial Growth Factor A - metabolism; Angiogenesis; Sprint interval exercise; HIF-1α; High-intensity training; Mitochondrial biogenesis
• ISSN: 1439-6319; 1439-6327
• DOI: 10.1007/s00421-016-3402-2

Purpose The effects of low-volume interval and continuous ‘all-out’ cycling, matched for total exercise duration, on mitochondrial and angiogenic cell signalling was investigated in trained individuals. Methods In a repeated measures design, 8 trained males ( V ˙ O 2 peak , 57 ± 7 ml kg −1  min −1 ) performed two cycling exercise protocols; interval (INT, 4 × 30 s maximal sprints interspersed by 4 min passive recovery) or continuous (CON, 2 min continuous maximal sprint). Muscle biopsies were obtained before, immediately after and 3 h post-exercise. Results Total work was 53 % greater ( P  = 0.01) in INT compared to CON (71.2 ± 7.3 vs. 46.3 ± 2.7 kJ, respectively). Phosphorylation of AMPK Thr172 increased by a similar magnitude ( P  = 0.347) immediately post INT and CON (1.6 ± 0.2 and 1.3 ± 0.3 fold, respectively; P  = 0.011), before returning to resting values at 3 h post-exercise. mRNA expression of PGC-1α (7.1 ± 2.1 vs. 5.5 ± 1.8 fold; P  = 0.007), VEGF (3.5 ± 1.2 vs. 4.3 ± 1.8 fold; P  = 0.02) and HIF-1α (2.0 ± 0.5 vs. 1.5 ± 0.3 fold; P  = 0.04) increased at 3 h post-exercise in response to INT and CON, respectively; the magnitude of which were not different between protocols. Conclusions Despite differences in total work done, low-volume INT and CON ‘all-out’ cycling, matched for exercise duration, provides a similar stimulus for the induction of mitochondrial and angiogenic cell signalling pathways in trained skeletal muscle.