Physiological Effects of Concurrent Training in Elderly Men

TLDR

The study examined how concurrent strength and endurance training affect neuromuscular and hormonal outcomes in elderly men. Twenty‑three healthy men aged 65±4 were randomized into concurrent, strength, or endurance groups, each training three times weekly for 12 weeks with strength, endurance, or combined protocols, and assessed for muscle strength, activation, and serum hormones. Concurrent training produced smaller gains in lower‑body strength and no upper‑body strength improvement compared to strength training alone, while endurance training alone decreased free testosterone; strength training alone yielded the greatest increases in isometric strength and maximal muscle activation, suggesting an interference effect on neural adaptations.

Abstract

The aim of the present study was to investigate the effects of concurrent strength and endurance training on neuromuscular and hormonal parameters in elderly men. 23 healthy men (65±4 years) were randomly assigned to 1 of 3 groups: concurrent (CG, n=8), strength (SG, n=8) or endurance group (EG, n=7). The programs consisted, of strength training, endurance training on a cycle ergometer or a combination of both in the same session 3 times per week over a duration of 12 weeks. Subjects were evaluated on parameters related to muscle strength, muscle activation and serum hormones. There were significant increases in lower-body strength in all groups (P<0.05), with higher increases in SG (67%) than CG (41%) and both were higher than EG (25%) (p<0.01). Only SG and CG increased upper-body strength (p<0.01), with no significant difference between the 2 groups. Furthermore, there were significant decreases in free testosterone in EG after training. Significant increases in isometric strength and maximal muscle activation (p<0.05) as well as decreases in the submaximal muscle activation to the same load, were only seen in SG (p<0.05). The present results suggest that the interference effect observed due to concurrent strength and endurance training could be related to impairment of neural adaptations.