We studied theinterrelations between, on the one hand, the physical activity (frequency, duration, intensity, and mode) measured by a questionnaire and, on the other, &OV0312;O2max(submaximal bicycle ergometer test) and the explosive muscle strength (vertical jumping height). A random sample of 774 health subjects from the city of turku participated in this study; the subjects were 25, 35, 45, or 55 yr of age. The &OV0312;O3maxof physically active 55-yr-old female subjects was on the same average level as of 25-yr-old females, who were physically inactive. Correspondingly, the average &OV0312;Omaxof physically active 55-yr-old males, who were physically inactive. With the exception of the oldest female study group, the jumpcing test of physically active subjects gave similar results as those of their inactive counterparts who were 10 yr younger. On the basis of the sports events reported by the subjects, we classified the subjects into five activity mode categories. The mode of activity was significantly associated with &OV0312;Omaxin a three-way anova (P= 0.0027) as well as with as with the jumping test result (P= 0.0001_. Mixed training (includes varied types fo exercise for the neuromuscular system) was the most beneficial mode of exercise for developing jumping height. The study suggests that the intensity, freqency, and duration of regular physical activity habits during leisure are associated with both &OV0312;Omaxand the jumping height, and that the jumping height results, in particular, are increased by mixed training.