Exploring the potential association between oral contraceptive use and risk of low energy availability with fitness adaptations and training loads in female university soccer players.

Abstract

Background: The research underrepresentation of female athletes has left gaps in understanding factors influencing female athlete performance. We aimed to examine the impact of oral contraceptive (OC) use and low energy availability (LEA) risk on training loads and physical fitness changes over a competitive season.

Methods: Eighteen female university soccer players completed fitness tests before and after the winter competitive season. Training loads were tracked over seven weeks using session rating of perceived exertion (sRPE). Reproductive factors, including OC use and LEA risk, were assessed through LEAF-Q. Two-way mixed ANOVA for repeated measures, with Bonferroni corrections, was applied. Correlations between LEAF-Q scores, weekly average sRPE, and fitness changes were examined.

Results: Weekly average sRPE ranged from 316±39 to 388±51 arbitrary units. No interaction was found between LEA risk or OC use and time, but time effects were significant (P<0.001), with week 5 sRPE > weeks 1-3, 6, and 7, and week 6 > week 7 (N.=18). Fitness improvements were noted post-season for aerobic fitness (YYRT-1; 19±31%), agility (IAT; -1.7±2.2%), sprint (-1.9±3.1%), broad jump (3.3±4.3%), and squats (18±16%) (P<0.05) in the whole sample. No LEA risk effects were found. Overall, OC users presented slower sprint speed at the baseline (F[1]=5.787; P=0.032) but no group-time interaction was found. A positive correlation was observed between week 7 sRPE and LEAF-Q score (r=0.507; P=0.032).

Conclusions: LEA risk and OC use presented no consistent association with training loads and fitness adaptations in university soccer players. Small sample size and sRPE monitoring focused on practices only limited the generalizability of our findings and a clearer understanding of the total weekly training load.