Molecular Adaptations to Concurrent Training

This study investigated the chronic effects of concurrent training (CT) on morphological and molecular adaptations. 37 men (age = 23.7 +/- 5.5 year) were divided into 4 groups: interval (IT), strength (ST) and concurrent (CT) training and a control group (C) and underwent 8 weeks of training. Maximum strength (1RM) and muscle cross-sectional area (CSA) were evaluated before and after training. Muscle samples were obtained before the training program and 48 h after the last training session. VO2max improved in 5 +/- 0.95 % and 15 +/- 1.3 % (pre- to post-test) in groups CT and IT, respectively, when compared to C. Time to exhaustion (TE) improved from pre- to post-test when compared to C (CT = 6.1 +/- 0.58 %; IT = 8.3 +/- 0.88 %; ST = 3.2 +/- 0.66 %). 1RM increased from pre-to post-test only in ST and CT groups (ST = 18.5 +/- 3.16 %; CT = 17.6 +/- 3.01 %). Similarly, ST and CT groups increased quadriceps CSA from pre-to post-test (6.2 +/- 1.4 %; 7.8 +/- 1.66 %). The p70S6K1 total protein content increased after CT. The ST group showed increased Akt phosphorylation at Ser473 (45.0 +/- 3.3 %) whereas AMPK phosphorylation at Thr172 increased only in IT group, (100 +/- 17.6 %). In summary, our data suggest that despite the differences in molecular adaptations between training regimens, CT did not blunt muscle strength and hypertrophy increments when compared with ST. (AU)