The effects of an 8-week yoga intervention on hamstring flexibility and sprint performance of rugby players

Abstract

Whether increased flexibility can improve sprint performance, among athletes is debatable. The purpose of this study was to evaluate the effect of an 8-week structured yoga intervention on flexibility and sprint performance of 18 male rugby union players, 19 ± 1.3 years old (mean ± SD). Players were assigned randomly to 2 groups; an experimental group (EG) that practiced yoga two times a week for 8 weeks and a control group (CG) that continued with their normal rugby training routine for the 8 weeks. Data were collected during pre-season and mid-season and included hamstring flexibility (sit and reach) and sprint performance (electronic timing). The EG had a small but non-significant increase in the sit and reach test of 3.0 ± 11.9 cm (mean ± SD) compared to the CG. Additionally, compared to CG, the 5, 10, and 30 metre sprint time of EG showed a small but non-significant improvement of -0.08 ± 0.11 s in sprint time. The changes in the flexibility from pre-to-post-test was moderately correlated with change in sprint time (r = -0.25, p<.01). Results indicate that improved hamstring flexibility may have a small to moderate beneficial effect on 5-30 metre sprint performance.