Sex differences in cardiovascular risk factor responses to resistance and endurance training in younger subjects

This study compared differences in cardiovascular (CV) risk factor responses between males and females following endurance (END) and resistance (RES) training. We present the frequency of responders to each training modality and the magnitude of response. Using a randomized crossover design, 68 healthy adults [age: female (F): 24.5 +/- 4.6; male (M): 27.3 +/- 6.6] completed 3 mo of RES and END, with 3 mo washout. Peak oxygen consumption (V_ O2peak), strength, body composition, blood pressure, glucose, insulin, and lipids were measured. V_ O2peak (L/min) significantly increased in both sexes following END, but not RES. The magnitude of change was larger in males (F: +0.20 L/min; M: +0.32 L/min), although this did not achieve statistical significance (P = 0.051). Strength significantly increased in both sexes following RES (P < 0.01), with a larger increase in males (Leg press: F: +39 kg; M: +63 kg; P < 0.05). Lean mass significantly increased in both sexes (P < 0.01) following RES and fat mass decreased in females following END (P = 0.019). The change in C-reactive protein following END was significantly different between sexes (F: -0.4 mg/L; M: +0.5 mg/L; P = 0.035). There were no differences between sexes in the proportion of individuals who responded positively to any variable following RES or END; differences between sexes were due to the magnitude of change. Males had a larger increase in V_ O2peak following END and strength following RES. There were no sex differences in other CV risk factors. This suggests differences in physiological responses to strength and V_ O2peak may not translate to changes in CV risk in healthy subjects. NEW & NOTEWORTHY This study investigated sex differences in cardiovascular risk factors in response to different exercise training modalities. Males had a larger improvement in peak oxygen consumption following endurance training and strength following resistance training compared with females. These changes in peak oxygen consumption and strength did not translate to changes in other cardiovascular risk factors. Despite the greater magnitude of change in males, there were no sex differences in the proportion of individuals who responded to training.