Swimming performances and stroking parameters in non skilled grammar school pupils: relation with age, gender and some anthropometric characteristics.

OBJECTIVE

It was hypothesized that swimming velocity (V) and stroking parameters such as stroke length (SL), stroke rate (SR) and stroke index (SI) are influenced by age, gender, and some anthropometric characteristics.

EXPERIMENTAL DESIGN

Cross-sectional study.

SETTING

Grammar school pupils from French schools.

PARTICIPANTS

One thousand and ninety-seven males and 961 females non skilled swimmers aged from 11 to 17.

INTERVENTIONS

Usual swimming sessions (6 +/- 2 h.year-1) during a physical education program at school.

MEASURES

V, SL, SF and SI (SI = V.SL) were measured or calculated from a 50-m crawl sprint and height, arm span and body mass were measured for all subjects.

RESULTS

The results showed that V, SL and SI increased regularly (p < 0.01) in relation to age in both genders. SL was never significantly different between males and females. SF remained unchanged according to age and was significantly higher in males than in females. V, SL and SI were influenced by age and arm span but not SF.

CONCLUSIONS

As males and females were submitted to the same swimming teaching program at school, a higher increase in muscle power and anaerobic capacity in males could explain the gender differences. These results observed in non skilled swimmers showed that the differences in stroking parameters between genders were the reverse of those of top level swimmers and that they can be used by swimming teachers in order to build some assessment tools and to better understand the improvements in swimming in relation to growth and gender.