Muscle strength and metabolism in master athletes

Abstract

Knee extensor muscle strength and metabolism were examined in endurance trained young versus master athletes (10 elderly: 62.5+/-4.1 yr and 10 young: 26.2+/-2.4 yr). Before and immediately after a resistance strength training (RST), subjects performed a maximal isometric voluntary contraction (MVC) and a 10-min cycling test at a same relative intensity. During MVC, evoked contractions of the knee extensors muscles were performed to assess neuromuscular properties. Metabolism was assessed using oxygen uptake kinetics model. Before the RST session master athletes showed lower knee extensors MVC values than young subjects (257 vs. 354 N p<0.05) without any difference in oxygen kinetics (respectively for elderly and young: oxygen slow component (VO2(sc)): 231 vs. 214 ml . min(-1) and time constant (tau1): 27.8 vs. 25.1 s, p>0.05). After the RST session, a similar effect of fatigue was observed on muscular properties and oxygen kinetics whatever the group (respectively for elderly and young: MVC: -13.4 vs. -15.9%; VO2(sc): +11.8 vs.+25.2% and tau1: -15.4 vs. -13.9%). Our results suggest that the ability of master athletes to perform exercise at a given intensity is maintained despite a significant loss in strength with ageing.