Intracyclic Velocity Variations and Arm Coordination During Exhaustive Exercise in Front Crawl Stroke

Abstract

The purpose of this study was to analyse the effects of an exhaustive exercise on arm coordination and intracyclic velocity variations (IVV) to better understand the ways in which they are modified under fatigue conditions. Seventeen competitive swimmers performed a 200-m all-out test and a set of two 25-m (before and after the 200-m) at maximal intensity to measure stroking parameters, IVV, and the relative duration of the different parts of the stroke cycle and identify the model of arm coordination by using the index of coordination (IdC). Results showed an increase in the relative duration of the propulsive time, which induced a change in arm coordination as fatigue developed in relation to a decrease in stroke length (SL) and stroke rate (SR) (p<0.05). The evolution of IdC corresponds to a reduction of the non-propulsive lag time between the two arms' propulsive actions. Despite these modifications, IVV were not significantly modified (p<0.05). The present results highlighted that IdC and relative durations of each part of the cycle (particularly the pull phase) could be assessed to complete the "SL x SR" model and to partly understand the technique modifications under fatigue condition.

Inter-Limb Coordinative Structure in a 200 m Front Crawl Event

“…In the fourth lap it was observed an IdC increase possible due to fatigue (as previously observed in 100m race [6]). In this fatigue stages, swimmers tend to increase their propulsive continuity, as observed elsewhere [7]. However, it further reflected more time spent during the propulsive phase than greater force generation as the v and SL decreased in the last 50m of the 200m.…”

Evaluation of muscle fatigue during 100-m front crawl

“…Seifert et al (2007) obtained similar results for the high-velocity male swimmers: the relative duration of the propulsive phase of the stroke was longer in the first lap with respect to the last lap, and the opposite results (the relative duration of the propulsive phase of the stroke was shorter) for the middle-and low-velocity swimmers. The increase of the relative propulsive (push and pull) phase occurring during fatiguing swim was also reported by Alberty et al (2008Alberty et al ( , 2005. It is possible that to maintain a stable stroke length in spite of accumulating fatigue, the swimmers extended the gliding phase of the stroke, which led to extension of the nonactive phase for the muscles and possibly also induced some changes in the arm coordination.…”

Embedded programming and real-time signal processing of swimming strokes

“…The forward velocity reached for swimmer Carrie Steinseifer, co-winner of the 100-m freestyle at the 1984 Olympic Games, was measured as 2 m/s, with a hand velocity of slightly less than 4 m/s. Throughout the race, velocity and stroke length decrease as fatigue develops, whereas stroke rate tends to remain constant and slightly increases at the end of the race [2]. It is known that a decrease in stroke length is related to a decrease in hand velocity during the propulsive phases of the stroke cycle [2].…”