et encore plus juste après la musculation
Aging Reduces the Activation of the mTORC1 Pathway after Resistance Exercise and Protein Intake in Human Skeletal Muscle: Potential Role of REDD1 and Impaired Anabolic Sensitivity
Marc Francaux Nutrients 2016, 8, 47
This study was designed to better understand the molecular mechanisms involved in
the anabolic resistance observed in elderly people. Nine young (22 0.1 years) and 10 older
(69 1.7 years) volunteers performed a one-leg extension exercise consisting of 10 10 repetitions
at 70% of their 3-RM, immediately after which they ingested 30 g of whey protein.
No age difference was measured in fasting insulin levels but the older subjects had
a 50% higher concentration than the young subjects in the fed state (p < 0.05). While no difference
was observed in the fasted state, in response to exercise and protein ingestion, the phosphorylation
state of PKB (p < 0.05 in Pro and Pro+ex) and S6K1 (p = 0.059 in Pro; p = 0.066 in Pro+ex) was
lower in the older subjects compared with the young subjects. After Pro+ex, REDD1 expression
tended to be higher (p = 0.087) in the older group while AMPK phosphorylation was not modified
by any condition.
In conclusion, we show that the activation of the mTORC1 pathway is reduced in skeletal muscle of older subjects after resistance exercise and protein ingestion compared with young subjects, which could be partially due to an increased expression of REDD1 and an impaired anabolic sensitivity.