INTRODUCTION: The capacity to reach high swimming velocities (v) is greatly dependent on biomechanical and physiological parameters. Additionally, the stroke temporal organization is also important to characterise highly skilled swimmers. Ten years ago Chollet et al. (2000) presented the Index of Coordination (IdC), a tool that assesses arm coordination. The assessment of the energy cost (C) is also well reported in the literature. Thus, it was aimed to assess the relationships between IdC and C at moderate to high intensities front crawl. METHODS: Seven high level swimmers performed a paced incremental protocol of 7x200m (0.05 m/s increments, 30s rest), until exhaustion (Fernandes et al., 2003). Oxygen consumption was measured through direct breathby-breath oximetry (K4b2, Cosmed) and blood lactate concentrations were assessed at rest, during the intervals, and immediately after each step (YSI1500LSport auto-analyser). C was assessed with data obtained both from aerobic and anaerobic energy pathways. Video analysis, obtained from two synchronized video cameras (JVC GR-SX1 SVHS) fixed on the lateral wall of the pool, was used in order to obtain the IdC value in all stages. RESULTS: During the incremental protocol, IdC and C increased, presenting very high relationships with v (r=0.99 and r=0.98, p<0.01, respectively. Despite InC and C were very highly correlated (r=0.99, p<0.01), when removing the effect of v (through partial correlation method), this relationship was not significant (r=0.42, p=0.40). DISCUSSION: The increase in swimming v implied a changed from a catch-up to an opposition mode (near to the VO2max intensities), which is in agreement with the literature (Chollet et al., 2000). Equally, C values also increased with v, as described before, seeming to be justified by the increasing power output necessary to overcome drag. The main finding was the very high direct relationship between IdC and C (r=0.99, p<0.01), which is in accordance with previous studies in terrestrial locomotion. However, the simple analysis of the r value shows that C increase with the increased continuity of technique (higher IdC), which seems to be paradoxal, being probably explainable by the fact that both parameters are strongly influenced by v. When it was removed the effect of v, it was observed that IdC and C do not correlate significantly.
© Copyright 2010 Biomechanics and Medicine in Swimming XI. Julkaistu Tekijä Norwegian School of Sport Sciences. Kaikki oikeudet pidätetään. / Kääntänyt https://www.DeepL.com/Translator