Effects of Oral Contraceptive Use on Exercise Capacity in Female Elite Soccer Players

The purpose of this project was to assess the effects of oral contraceptives (OC) on exercise capacity in female elite soccer players. Fourteen subjects (N=7 oral contraceptives users (OCU) + 7 non-OCU (N-OCU)) were recruited. An assessment of body composition was determined by Dual energy X ray absorptiometry and endogenous ovarian hormone concentrations in serum measured. A maximal treadmill test was performed to assess VO2, VCO2, blood glucose and blood lactate levels during exercise. The endogenous ovarian hormone concentrations were significantly lower among the OCU. After exercise testing OCU had significantly lower VO2 peak when normalised to total body weight or muscle mass, compared to the N-OCU. OCU had higher respiratory exchange ratio (RER) during submaximal exercise, indicating altered substrate utilization. The OCU had significant lower capillary blood glucose concentrations after exercise. The main finding of our study was that peak oxygen uptake was lower in female elite soccer players using OC than N-OCU, whether it is normalized to body weight or muscle mass. The difference appears to be related to effects on skeletal muscle metabolism