Consecutive bouts of diverse contractile activity alter acute responses in human skeletal muscle
Coffey, Vernon Glenn Pilegaard, Henriette Garnham, Andrew P. O'Brien, Brendan J. Hawley, John Alan
Coffey, Vernon Glenn
Pilegaard, Henriette
Garnham, Andrew P.
O'Brien, Brendan J.
Hawley, John Alan
Abstract
We examined acute molecular responses in skeletal muscle to divergent exercise stimuli by combining consecutive bouts of resistance and endurance exercise. Eight men [22.9 ± 6.3 yr, body mass of 73.2 ± 4.5 kg, peak O2 uptake (V̇o2peak) of 54.0 ± 5.7 ml·kg−1·min−1] were randomly assigned to complete trials consisting of either resistance exercise (8 × 5 leg extension, 80% 1 repetition maximum) followed by a bout of endurance exercise (30 min cycling, 70% V̇o2peak) or vice versa. Muscle biopsies were obtained from the vastus lateralis at rest, 15 min after each exercise bout, and after 3 h of passive recovery to determine early signaling and mRNA responses. Phosphorylation of Akt and Akt1Ser473 were elevated 15 min after resistance exercise compared with cycling, with the greatest increase observed when resistance exercise followed cycling (∼55%; P < 0.01). TSC2-mTOR-S6 kinase phosphorylation 15 min after each bout of exercise was similar regardless of the exercise mode. The cumulative effect of combined exercise resulted in disparate mRNA responses. IGF-I mRNA content was reduced when cycling preceded resistance exercise (−42%), whereas muscle ring finger mRNA was elevated when cycling was undertaken after resistance exercise (∼52%; P < 0.05). The hexokinase II mRNA level was higher after resistance cycling (∼45%; P < 0.05) than after cycling-resistance exercise, whereas modest increases in peroxisome proliferator-activated receptor gamma coactivator-1α mRNA did not reveal an order effect. We conclude that acute responses to diverse bouts of contractile activity are modified by the exercise order. Moreover, undertaking divergent exercise in close proximity influences the acute molecular profile and likely exacerbates acute “interference.”
Keywords
endurance, resistance exercise, acute responses, concurrent training
Date
2009
Type
Journal article
Journal
Journal of Applied Physiology
Book
Volume
106
Issue
4
Page Range
1187-1197
Article Number
ACU Department
Centre for Exercise and Nutrition
Faculty of Health Sciences
Mary MacKillop Institute for Health Research
Faculty of Health Sciences
Mary MacKillop Institute for Health Research