Differences in swimming smoothness between elite and non-elite swimmers

ABSTRACT

The aim of the study was to investigate whether jerk cost (JC) can discriminate between swimming levels. Nine elite and nine non-elite swimmers swam a 50-m front-crawl sprint wearing a 3D accelerometer on their back between the inferior angles of the scapulae. Lap times and JC were calculated from the acceleration signal and compared between groups and between swimmers within a group. The elite swimmers swam significantly faster lap times than the non-elite swimmers (p < 0.001). They did so with significantly lower levels of JC compared to the non-elite swimmers (p = 0.005). Furthermore, a stepwise multiple linear regression showed JC accounted for 32.9% of the variation in lap time of the elite swimmers. These results indicate that it is possible to discriminate elite from non-elite swimmers using JC: elite swimmers swim with lower JCs than non-elite swimmers. Additionally, swimming at higher speed is associated with more accelerations and decelerations in both elite and non-elite swimmers, which is reflected by higher JCs and lower smoothness. In sum, JC provides an index of swimming technique that is easy to use in training practice.

KEYWORDS:

• Jerk
• accelerometry
• daily monitoring
• technique
• efficiency

Acknowledgments

We would like to thank Jaap Harlaar and Robert Ton for their assistance in the normalisation of the strokes, Levy Hoeven for his assistance in performing the measurements and the participating swimmers for their time and effort. All three were affiliated to the Department of Human Movement Sciences, Faculty of Behavioural and Movement Sciences, Free University Amsterdam, The Netherlands, during the study’s conductance.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Correction Statement

This article has been republished with minor changes. These changes do not impact the academic content of the article.

Additional information

Funding

This research is supported by the Dutch Technology Foundation STW under [Grant 12887]. STW is part of the Netherlands Organization for Scientific Research (NWO) and which is partly funded by the Ministry of Economic Affairs. The results of the current study do not constitute an endorsement of the product by the authors or the journal.