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 cross-over design trial in which all participants completed 12-weeks END and RES, separated by a 12-week washout. Echocardiograms assessed morphology (left ventricular mass, LVM), systolic function (ejection fraction, EF, and global longitudinal strain, GLS), 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), while E/e' increased (Δ 0.74 ± 1.08, P = 0.004, indicating a decline in diastolic function). 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 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, indicating an improvement in diastolic function). Systolic function was not impacted significantly by END or RES in either sex. Our data suggests that females were less responsive to RES training than males, that RES increased LVM and caused a decline in diastolic function (i.e. an increase in E/e') in males, whereas END improved E/e' (i.e. decreased) in females. These data suggest that sex differences exist in cardiac structural and functional adaptations to different forms of exercise training.
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