Countermovement Jump Force-Time Curve Analysis in Female Athletes at Risk of REDs

Mountjoy et al., 2023) highlighted the need for further research into how REDs may impact neuromuscular qualities with the countermovement jump (CMJ) listed as a preferred method to assess decreased power performance. Therefore, this study investigated if CMJ performance differed in female athletes at risk of REDs compared to those not at risk. 88 female team sport athletes (20 ± 6.0yrs) volunteered to participate in the study. With institutional ethics approval, all participants completed the LEAF-Q and EDE-Q and were defined as REDs Mild Risk (n = 17) or REDs No-Risk (n = 71) as per recent IOC recommendations to indicate primary and secondary indicators of REDs, such as impaired reproductive function, gastrointestinal function, and mental health. Following this, all participants performed the CMJ in which force-time discrete analysis of CMJ sub-phases (unloading, eccentric, concentric) was completed. Additionally, statistical parametric mapping (SPM) was used to assess differences between groups for force–, power–, velocity–, and displacement–time curves. For all force-time discrete measures, differences between groups were not statistically significant (p > 0.05) with trivial to small effect sizes observed (g* range with 95% CI = 0.00 – 0.47 (-0.53-1.02)). SPM analysis also found no statistically significant (p > 0.05) differences between groups for continuous curve measures. The findings from this study suggest that acute neuromuscular qualities may not be different in female athletes who are at mild risk of REDs. This may be because short duration, maximal performance may not be sensitive to the negative effects of REDs symptoms. Future research is needed to establish the usefulness of the CMJ as a method to study the outcomes of REDs on power performance whether this is influenced by the risk/severity of REDs symptoms.