Body Composition And Oral Contraceptive Use In Young Female Athletes

The use of oral contraceptives (OC) has been shown to influence biomarkers, training adaptations and body composition in adult female athletes. However, less is known regarding how current OC use may influence body composition parameters in younger female athletes. PURPOSE: To examine differences in body composition among a cohort of young female athletes. METHODS: Forty-one high school (n = 12) and collegiate (n = 29) female athletes (Age: 18.73 ± 2.0 years; height: 1.67 ± 0.07 m; body mass: 61.9 ± 8.9 kg; body fat %: 22.14 ± 5.9%) participated in the current study. All athletes were instructed to fast (>8 hrs.) and refrain from strenuous activity (>12 hrs.) prior to testing. Prior to body composition measurements, athletes had their hydration levels assessed using a urine specific gravity (USG) refractometer, with ≤1.02 required of athletes to indicate euhydration. Body volume was then assessed using air displacement plethysmography and total body water (TBW) was assessed using bioelectrical impedance spectroscopy. Using a three-compartment model, fat-free mass (FFM), fat mass (FM) and body fat percentage (BF%) were then calculated using the Siri equation. Athletes also completed a demographics questionnaire to assess contraceptive use. Cohen’s d was calculated to assess effect sizes for differences in body composition variables. RESULTS: Thirteen of 41 (31.7%) athletes reported current OC use. Of those reporting current OC use, the top reasons for use were: 1) Contraception (n = 3; 23%); 2) Reduction of menstruation pains (n = 3; 23%); 3) Regulate the menstrual cycle in relation to performance (n = 3; 23%); 4) Reduction of bleeding (n = 2; 15%); and 5) Other (n = 2; 15%). No significant differences in BF% (OC: 24.1 ± 5.1 vs. Non-OC: 21.1 ± 6.2 %; p = 0.16; ES = 0.53), FFM (OC: 48.4 ± 4.5 vs. Non-OC: 48.7 ± 5.2 kg; p = 0.83; ES = 0.06) or FM (OC: 15.4 ± 3.9 vs. Non-OC: 13.9 ± 5.4 kg; p = 0.384; ES = 0.32) were observed in those reporting current OC use versus non-OC users. CONCLUSIONS: A third of the young female athletes in the current study reported current OC use. Oral contraceptive users did not present with any significant differences in measures of body composition. A small effect size was observed for differences in BF%, suggesting that OC users may have a slightly higher BF% compared to non-OC users.