Comparison of aerobic exercise capacity and muscle strength in overweight women with and without polycystic ovary syndrome

OBJECTIVE: To assess maximal aerobic capacity (VO2max) and muscle strength in overweight and obese women with polycystic ovary syndrome (PCOS) and determine their relationship with metabolic and hormonal factors. DESIGN: Cross-sectional study. SETTING: Clinical Research Unit. POPULATION: Overweight and obese women with PCOS (n = 10) and age-and weight-matched healthy controls (n = 16). METHODS: VO2max was measured during an incremental treadmill test and maximal isometric (ImS) and isokinetic knee extensor strength (IkS) (120 degrees/second) were assessed by isokinetic dynamometry. MAIN OUTCOME MEASURES: VO2max, ImS, IkS, waist circumference, blood lipids, glucose, insulin, insulin resistance (homeostatic model assessment HOMA2), C-reactive protein (CRP), hormonal profile. RESULTS: PCOS women had higher levels of testosterone and free testosterone (P < or = 0.05), but there were no significant differences in any cardiovascular disease (CVD) risk markers between the groups. VO2max was similar in women with PCOS and healthy controls (PCOS 26.0 +/- 4.1 ml/kg/minute, controls 25.7 +/- 3.8 ml/kg/minute; P = 0.90), as was ImS (PCOS 1.50 +/- 0.54 Nm/kg, controls 1.50 +/- 0.47 Nm/kg; P = 0.96) and IkS (PCOS 1.04 +/- 0.32 Nm/kg, controls 1.16 +/- 0.23 Nm/kg; P = 0.32). VO2max was inversely related to waist circumference, insulin, HOMA2 and CRP. Waist circumference was inversely associated with ImS and IkS. No significant associations between exercise parameters and hormonal variables were identified. CONCLUSIONS: Compared to age- and weight-matched healthy overweight and obese women with similar insulin resistance and CVD risk profiles, women with PCOS had similar aerobic capacity and muscle strength. This suggests PCOS, at least in the absence of an adverse metabolic profile is unlikely to limit physical function. Larger studies examining the effects of PCOS on exercise tolerance in a diverse range of PCOS phenotypes is required.