Elderly oarsmen have larger trunk and thigh muscles and greater strength than age-matched untrained men.

To evaluate whether regularly performed rowing exercise affects the trunk muscles size and function, and to examine the effect of rowing exercise on thigh muscle size and function in elderly rowers, we compared the cross-sectional area (CSA) and strength of these muscles in elderly male rowers and in age-matched untrained men. Participants were 16 elderly rowing-trained men (ROW age, 67.8 +/- 2.3 years) and 18 elderly untrained men (CON 66.2 +/- 3.0 years). CSA was measured by MRI in the trunk and thigh muscles. Isometric trunk flexion force and leg extension power were measured. ROW had a 20% larger total trunk muscle CSA than CON (P < 0.01); rectus abdominis was 27% larger, psoas major 64% larger, and erector spinae 14% larger in ROW than in CON (P < 0.05-0.001). Isometric trunk flexion force was related to the CSA of the rectus abdominis (r = 0.777, P < 0.001) and psoas major (r = 0.694, P < 0.001), and was 42% larger in ROW than in CON (P < 0.001). However, force adjusted for the CSA of the muscles did not differ significantly between CON and ROW. In ROW, the CSA was 13% larger in the total thigh muscles (P < 0.01), and leg extension power was 43% higher than in CON (P < 0.001). These results suggest that rowing exercise is a favorable training modality for the trunk muscles, especially psoas major and that it improves thigh muscle size and function in elderly men.