Medicine & Science in Sports & Exercise. 46(1):156–166, JAN 2014
DOI: 10.1249/MSS.0b013e3182a32b72
Ovarian Suppression Impairs Sport Performance in Junior Elite Female Swimmers
Jaci VanHeest;Carol Rodgers;Carrie Mahoney;Mary De Souza;
1Departments of Educational Psychology and Kinesiology, University of Connecticut, Storrs, CT; 2College of Kinesiology, University of Saskatchewan, Saskatchewan, CANADA; and 3Department of Kinesiology, Pennsylvania State University, University Park, PA
IntroductionCompetitive female athletes restrict energy intake and increase exercise energy expenditure frequently resulting in ovarian suppression. The purpose of this study was to determine the impact of ovarian suppression and energy deficit on swimming performance (400-m swim velocity).MethodsMenstrual status was determined by circulating estradiol (E2) and progesterone (P4) in ten junior elite female swimmers (15–17 yr). The athletes were categorized as cyclic (CYC) or ovarian-suppressed (OVS). They were evaluated every 2 wk for metabolic hormones, bioenergetic parameters, and sport performance during the 12-wk season.ResultsCYC and OVS athletes were similar (P > 0.05) in age (CYC = 16.2 ± 1.8 yr, OVS = 17 ± 1.7 yr), body mass index (CYC = 21 ± 0.4 kg·m−2, OVS = 25 ± 0.8 kg·m−2), and gynecological age (CYC = 2.6 ± 1.1 yr, OVS = 2.8 ± 1.5 yr). OVS had suppressed P4 (P < 0.001) and E2 (P = 0.002) across the season. Total triiodothyronine (TT3) and insulin-like growth factor (IGF-1) were lower in OVS (TT3: CYC = 1.6 ± 0.2 nmol·L−1, OVS = 1.4 ± 0.1 nmol·L−1, P < 0.001; IGF-1: CYC = 243 ± 1 μg·mL−1, OVS = 214 ± 3 μg·mL−1P < 0.001) than CYC at week 12. Energy intake (P < 0.001) and energy availability (P < 0.001) were significantly lower in OVS versus CYC. OVS exhibited a 9.8% decline in Δ400-m swim velocity compared with an 8.2% improvement in CYC at week 12.ConclusionsOvarian steroids (P4 and E2), metabolic hormones (TT3 and IGF-1), and energy status markers (EA and EI) were highly correlated with sport performance. This study illustrates that when exercise training occurs in the presence of ovarian suppression with evidence for energy conservation (i.e., reduced TT3), it is associated with poor sport performance. These data from junior elite female athletes support the need for dietary periodization to help optimize energy intake for appropriate training adaptation and maximal sport performance.