Dekerle, J., Nesi, X., Lefevre, T., Depretz, S., Sidney, M., Marchand, F. H., & Pelayo, P. (2005). Stroking parameters in front crawl swimming and maximal lactate steady state speed. International Journal of Sports Medicine, 26, 53-58.

This study ascertained whether the maximal speed from which the stroke length decreases significantly corresponds to the maximal lactate steady state swimming speed, and examined the effect of exercise duration on stroking parameters above, below, and at the lactate steady state swimming speed. Well-trained male swimmers (N = 11) performed an all-out 400-m front crawl test to estimate maximal aerobic speed and four sub-maximal 30-minute tests (75, 80, 85, and 90% maximal aerobic speed) to determine the maximal lactate steady state swimming speed and the significant stroke-length drop. Changes in stroking parameters were analyzed throughout these tests.

Maximal lactate steady state swimming speed and the significant stroke-length drop were not significantly different from each other and were highly correlated (r = 0.88). A slight stroke rate increase, and a stroke length decrease, were observed above the maximal lactate steady state swimming speed but were only significant for the five Ss unable to maintain that speed for 30 minutes. During the 30-minute tests swum under and at the maximal lactate steady state swimming speed, stroking parameters were stable.

Implication. The maximal lactate steady state swimming speed represents not only a physiological transition threshold between heavy and severe sub-maximal intensities but also a biomechanical boundary beyond which stroke length becomes compromised.

Return to Table of Contents for Physiology of Swimming.