Fig. 1

a Final body weight (BW), b wet heart weight (HW) normalized by BW, and c dry HW normalized by BW in 2, 4, 6, and 8-week swimming rats and their age-matched sedentary controls. Final BW was measured at the ends of 2, 4, 6, or 8-week swimming sessions. *P < 0.05, **P < 0.01, ***P < 0.001 compared with the corresponding age-matched sedentary controls. Numbers in parentheses are the numbers of animals