Sex-stratified associations between isokinetic strength, core endurance, and dynamic balance in elite youth rowers: a cross-sectional study

This study investigated the relationships among lower-extremity isokinetic strength, core endurance, and dynamic balance in female and male elite adolescent rowers. Sixty-eight elite adolescent rowers (32 females and 36 males) affiliated with the Turkish Rowing Federation participated. Knee muscle strength was assessed using isokinetic dynamometry, core endurance using the McGill trunk endurance tests, and dynamic balance using the Y Balance Test. Sex-stratified correlations were examined using Pearson or Spearman correlation analyses with Benjamini–Hochberg false discovery rate (FDR) adjustment for multiple comparisons. A hierarchical multiple linear regression analysis was performed to examine whether core endurance and body-mass-normalized lower-extremity strength provided additional explanatory value for dynamic balance beyond sex, anthropometric, and training-related covariates. Sex-by-predictor interaction analyses were additionally performed to assess whether selected associations differed by sex. Male athletes exhibited greater body-mass-normalized knee muscle strength and trunk extensor endurance, whereas female athletes achieved higher normalized Y Balance Test composite scores. After FDR correction, trunk extensor endurance was positively associated with body-mass-normalized dominant-leg quadriceps peak torque, and body-mass-normalized dominant-leg quadriceps peak torque was positively associated with body-mass-normalized dominant-leg hamstring peak torque in the overall sample. No associations between dynamic balance and the measured neuromuscular variables remained significant in the overall sample after FDR correction. In sex-stratified analyses, core flexor endurance and body-mass-normalized dominant-leg quadriceps peak torque were positively associated with dynamic balance in males, whereas no significant correlations were observed in females. However, neither the Sex × Core Flexor Endurance nor the Sex × Dominant Quadriceps Strength interaction was statistically significant ( p = 0.722 and p = 0.509, respectively). In the hierarchical regression analysis, the addition of core endurance and body-mass-normalized knee strength variables did not significantly improve the explained variance in dynamic balance beyond the covariates. Female and male elite adolescent rowers differed in normalized knee strength, trunk extensor endurance, and dynamic balance. Although selected associations emerged in males, the absence of significant sex-by-predictor interactions indicates that these patterns should be considered exploratory rather than sex-specific. Overall, the findings suggest that strength, trunk endurance, and dynamic balance reflect complementary but partly distinct dimensions of neuromuscular function.