The aim of this study was to assess the interaction of kinematic, kinetic, and energetic variables as speed predictors in
adolescent swimmers in the front-crawl stroke. Design: Ten boys (mean age [SD] = 16.4 [0.7] y) and 13 girls (mean age
[SD] = 14.9 [0.9] y) were assessed. Methods: The swimming performance indicator was a 25-m sprint. A set of kinematic, kinetic
(hydrodynamic and propulsion), and energetic variables was established as a key predictor of swimming performance. Multilevel
software was used to model the maximum swimming speed. Results: The final model identified time (estimate = −0.008,
P = .044), stroke frequency (estimate = 0.718, P < .001), active drag coefficient (estimate = −0.330, P = .004), lactate concentration
(estimate = 0.019, P < .001), and critical speed (estimate = −0.150, P = .035) as significant predictors. Therefore, the
interaction of kinematic, hydrodynamic, and energetic variables seems to be the main predictor of speed in adolescent swimmers.
Conclusions: Coaches and practitioners should be aware that improvements in isolated variables may not translate into faster
swimming speed. A multilevel evaluation may be required for a more effective assessment of the prediction of swimming speed
based on several key variables rather than a single analysis
This work is supported by national funds (FCT–Portuguese Foundation
for Science and Technology) under the project UIDB/DTP/04045/2020.
