Longitudinal Relationships Between Maturation, Technical Efficiency, and Performance in Age-Group Swimmers: Improving Swimmer Evaluation.

The study aimed to (1) accurately examine longitudinal relationships between maturity status and both technical skill indices and performance in Australian male (N = 64) age-group Front-crawl swimmers (10-15 y) and (2) determine whether individual differences in maturation influenced relationships between technical skill level and swimming performance. A repeated-measures design was used to assess maturity status and performance on 200-m Front-crawl trial across 2 competition seasons (2018-2020). Assessments were made on 3 to 5 occasions (median = 3) separated by approximately 4 months. Average horizontal velocity and stroke frequency were used to calculate technical skill indices, specifically stroke index, and arm propelling efficiency. Relationships between variables were assessed using linear mixed models, identifying fixed, and random effect estimates. Curvilinear trends best described significant longitudinal relationships between maturity status with horizontal velocity (F = 10.33 [1, 233.77]; P = .002) and stroke index (F = 5.55 [1, 217.9]; P = .02) during 200-m Front-crawl trials. Maturity status was not significantly related to arm propelling efficiency (P = .08). However, arm propelling efficiency was an independent predictor of Front-crawl velocity (F = 55.89 [1, 210.45]; P < .001). Maturity status predicted assessment of swimmer technical skill (stroke index) and swimming performance. However, technical skill accessed via arm propelling efficiency was independent of maturation and was predictive of performance. Maturity status influences performance evaluation based on technical skill and velocity. Findings highlight the need to account for maturation and technical skill in age-group swimmers to better inform swimmer evaluation.