Mental Toughness and 2K Rowing Performance in Division II Female Collegiate Athletes: A Longitudinal Analysis Using Mixed-Effects Modeling.
Mental toughness (MT) may contribute to within-athlete rowing performance variation, yet longitudinal evidence remains sparse. This pilot study examined within-athlete associations between MT and 2K ergometer performance across a competitive season in Division II female rowers. Twelve athletes (age 20.8 ± 2.1 years) completed the mental toughness index (MTI) before four standardized 2K time trials. Performance was modeled using a linear mixed-effects model with a random intercept for the athlete. The MTI was decomposed into within- and between-athlete components, with the timepoint as a categorical covariate. Small-sample inference used CR2 cluster-robust standard errors with Satterthwaite degrees of freedom. Performance improved mid-season relative to baseline (Timepoint 3: -7.29 s; 95% CI [-13.29, -1.29]; p = 0.023). The within-athlete MTI association was small and imprecise (β = -0.48 s/point; 95% CI [-1.56, 0.59]; p = 0.311), and the between-athlete MTI was unassociated with performance (β = 0.70; p = 0.667). Stable between-athlete differences dominated over variability (ICC = 0.946; R2m = 0.033; R2c = 0.948). The within-athlete MTI estimate was small and imprecise; given the wide compatibility interval, both the direction and magnitude of the association remain highly uncertain, and this inconclusive finding should not be interpreted as evidence of absence. Future studies with larger samples and key covariates (e.g., training load and illness/injury) are needed to confirm these preliminary estimates.