Longitudinal Changes in Countermovement Jump and Isometric Mid-Thigh Pull Metrics and Their Relationship With...

Aguila Camacho, A, Ochoa Ahmed, F, Rowlett, M, Ríos-Gallardo, PT, Cabarkapa, DV, Cabarkapa, D, and Montalvo, S. Longitudinal changes in countermovement jump and isometric mid-thigh pull metrics and their relationship with on-court basketball performance in elite female collegiate basketball players. J Strength Cond Res 40(9): 1095-1102, 2026-To quantify within-subject relationships among countermovement jump (CMJ) and isometric mid-thigh pull (IMTP) variables, describe their temporal behavior across a competitive season, and examine their association with game performance in female collegiate basketball. Eighteen athletes (21.6 ± 1.9 years; 69.9 ± 9.1 kg; 171.6 ± 8.2 cm) completed CMJ and IMTP testing for 33 weeks. Within-subject (demeaned) Spearman correlation matrices were used to identify functional clusters. Representative CMJ (jump height, peak power, contraction time, reactive strength index(mod) and IMTP (peak force, impulse 100 ms, rate of force development [RFD] 50 ms) variables were modeled longitudinally with linear mixed-effects models (random intercepts; autoregressive (1) for a week). Game outcomes from 24 contests were linked to the nearest prior test and evaluated with bivariate Spearman correlations and leave-one-out cross-validated (LOOCV) linear models. Countermovement jump variables clustered into (a) force-production measures (e.g., impulses/peak power; moderate-high positive associations), (b) performance outcomes (jump height with relative power), and (c) temporal measures (contraction/phase durations). Isometric mid-thigh pull variables formed tight early impulse and RFD clusters, with peak-force measures grouping separately. Cross-test associations were generally small (|ρ| ≤ ∼0.30), indicating complementary constructs. Mixed-model marginal means showed modest, nonuniform seasonal trends-modified reactive strength index (mRSI) tended to increase and contraction time to decrease late season, while IMTP peak force exhibited a mid-season rise-amid substantial within-player variability. For game performance, only mRSI showed a statistically significant positive correlation with point differential (ρ = 0.46, p = 0.024); other variables were small and nonsignificant. Single-variable LOOCV models explained little variance in point differential (R 2 _cv ≤ 0.04). Countermovement jump and IMTP capture largely independent neuromuscular qualities and exhibit modest, test-specific seasonal changes. Although mRSI relates positively to game point differential, single neuromuscular metrics showed limited standalone predictive value, supporting their use primarily for monitoring readiness in conjunction with contextual factors rather than for game-to-game prediction.