Comparative physiological profiles among young and middle-aged female distance runners.

Physiological profiles of 42 middle-aged female marathoners (MAM) (means age = 38.2 yr) were compared with those of 9 young female marathoners (YM) (means age = 25.2 yr), 10 middle-aged female 10-km runners (MATK) (means age = 33.1 yr), and 37 middle-aged sedentary women (MAS) (means age = 38.8 yr). The groups were equivalent for height, maximum heart rate, and hematocrit, and, after adjusting for body size, hemoglobin concentration, lipids, and lipoproteins. Compared to the runners, MAS subjects had significantly higher resting heart rates and significantly lower treadmill performance times, maximum exercise minute ventilation, and VO2max. Compared to YM subjects, MATK runners had higher resting heart rates and lower treadmill performance times, and compared to both groups of marathoners, MATK runners had lower VO2max, but only when expressed relative to body weight. The YM and MAM subjects did not differ from each other except for resting heart rate values, which were higher in the MAM. These data suggest that runners have more favorable cardiorespiratory profiles than do sedentary women, but that lipid and lipoprotein values may be affected more by body size than by activity level.