The Effect of Aging on Relationships between Lean Body Mass and VO(2)max in Rowers

Aging is associated with a fall in maximal aerobic capacity as well as with a decline in lean body mass. The purpose of the study was to investigate the influence of aging on the relationship between aerobic capacity and lean body mass in subjects that chronically train both their upper and lower bodies. Eleven older rowers (58±5 yrs) and 11 younger rowers (27±4 yrs) participated in the study. Prior to the VO(2)max testing, subjects underwent a dual energy X-ray absorptiometry scan to estimate total lean body mass. Subsequently, VO(2)max was quantified during a maximal exercise test on a rowing ergometer as well as a semi-recumbent cycle ergometer. The test protocol included a pre-exercise stage followed by incremental exercise until VO(2)max was reached. The order of exercise modes was randomized and there was a wash-out period between the two tests. Oxygen uptake was obtained via a breath-by-breath metabolic cart (Vmax(™) Encore, San Diego, CA). Rowing VO(2)max was higher than cycling VO(2)max in both groups (p<0.05). Older subjects had less of an increase in VO(2)max from cycling to rowing (p<0.05). There was a significant relationship between muscle mass and VO(2)max for both groups (p<0.05). After correcting for muscle mass, the difference in cycling VO(2)max between groups disappeared (p>0.05), however, older subjects still demonstrated a lower rowing VO(2)max relative to younger subjects (p<0.05). Muscle mass is associated with the VO(2)max obtained, however, it appears that VO(2)max in older subjects may be less influenced by muscle mass than in younger subjects.