Fernandes, R. J., Morais, P., Keskinen, K. L., Seifert, L., Chollet, D., & Vilas-Boas, J. P. (2010). Relationship between arm coordination and energy-cost in front crawl swimming. A paper presented at the XIth International Symposium for Biomechanics and Medicine in Swimming, Oslo, June 16–19, 2010.

This study assessed the relationships between the Index of Coordination and energy cost at moderate to high intensities of front crawl swimming in high level swimmers (N = 7). Ss performed a paced incremental protocol of 7 x 200 m (0.05 m/s increments, 30 seconds rest), until exhaustion. Oxygen consumption was measured directly breath-by-breath. Blood lactate concentrations were assessed at rest, during the intervals, and immediately after each step. Energy cost was estimated from data obtained both from the aerobic and anaerobic energy pathways. The Index of Coordination was analyzed from two lateral-view synchronized video cameras.

The Index of Coordination and energy cost increased and were significantly and very highly related to velocity. When the effect of velocity was partialed out from the relationships, the Index of Coordination and energy cost were not related [that means the two factors changed because of different factors as velocity increased].

Implication. As swimming velocity increases, crawl stroke technique changes from a catch-up to an opposition mode (near to the VO2max intensities), which is in agreement with past literature. Increases in energy cost occur independently of the alterations in technique. Catch-up stroking is not a technique that should be encouraged when one wants to swim faster.

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