Is Front Crawl Swimming Performance Affected By Hydrodynamic Drag In Young Swimmers?

Abstract

Swimming performance is affected by several factors including the hydrodynamic drag. Hydrodynamic drag is the force that a swimmer has to overcome in order to maintain his movement through water and is highly dependent on swimming technique. PURPOSE: To analyse in young swimmers the relationship between hydrodynamic drag and the front crawl performance. METHODS: 25 young swimmers (11 females and 14 males) participated in this study. Their mean (standard deviation) age, body mass, height and best swimming performance in 100 m front crawl was 12.08 (0.76) years, 43.08 (7.60) kg, 1.52 (0.08) m and, 75.11 (9.57) s, respectively. All swimmers belonged to the same swimming club and were trained by the same coach for two years. Active drag measurements were conducted in a 25 m swimming pool. The velocity perturbation method was used to determine active drag in front crawl and in-water starts were used. The performance in 100 m, 200 m, 400 m, 800 m and 1500 m short course front crawl events were related to active drag data (drag force and drag coefficient values) using Pearson correlation coefficient. RESULTS: A significant correlation (p<0.05) was found between the drag force and the performance in 100 m and 200 m (r=-0.60, r=-0.58, respectively). Drag coefficient values were not related to any of the front crawl events. Moreover, hydrodynamic drag parameters were not related to 400 m, 800 m and 1500 m front crawl events. CONCLUSIONS: In young swimmers the performance in short distance events (100 m and 200 m) seems to be dependent on drag force. The same situation does not occur with middle distance events (400, 800 and 1500 m). Therefore, the swimmers who presented higher values of hydrodynamic drag force presented better performances in 100 and 200 m front crawl. These findings plus the absence of any relation between performance and drag coefficient suggested that in these ages other aspects of swimming technique (namely propelling efficiency) can play an important role to achieve higher velocities and thus, higher performances. This increase in swimming velocity leads, as a consequent, to an increase in drag values, although drag coefficient remains almost unchanged.