Impact of Sex on Cardiac Functional Adaptation to Different Modes of Exercise Training: A Randomized Crossover Study

We hypothesized that male and female volunteers would exhibit distinct changes in cardiac morphology, systolic, and diastolic function following endurance (END) and resistance (RES) training.

Thirty-eight females and 26 males participated in a randomized crossover design trial in which all participants completed 12-wk END and RES, separated by a 12-wk washout. Echocardiograms assessed morphology (left ventricular mass (LVM)), systolic function (ejection fraction and global longitudinal strain), diastolic function (mitral valve velocities (E, A); tissue Doppler velocities (e', a')), and left atrial volume.

Males responded to RES by increasing LVM (Δ 9.1 ± 14.3 g, P = 0.005), whereas E/e' increased (Δ 0.74 ± 1.08, P = 0.004). There were no significant changes in females following RES. In response to END, LVM increased in both males (Δ 8.8 ± 15.7 g, P = 0.008) and females (Δ 6.5 ± 12.5 g, P = 0.004), with no significant difference in E/e' (Δ -0.29 ± 0.90) in males but a significant difference in females (Δ -0.39 ± 1.06, P = 0.012). Systolic function was not impacted significantly by END or RES in either sex.

Our data suggest that females were less responsive to RES training than males, and that RES increased LVM and caused an increase in E/e' in males, whereas END decreased E/e' in females. These data suggest that sex differences exist in cardiac structural and functional adaptations to different forms of exercise training.