# Physical Education-Based Stretching During Warm-Up, Cool-Down, or Both on Back-Saver Sit-and-Reach Scores in Schoolchildren

## TL;DR

This study compares the effectiveness of stretching during warm-up, cool-down, or both in improving hamstring flexibility in schoolchildren.

## Contribution

The study identifies that stretching during cool-down is more effective than warm-up or combined sessions for improving hamstring extensibility in children.

## Key findings

- Stretching during cool-down significantly improved hamstring extensibility compared to warm-up or combined sessions.
- The cool-down group increased the percentage of children with healthy hamstring flexibility from 49% to 66%.
- The findings suggest that stretching during cool-down is a feasible and effective strategy in physical education.

## Abstract

Objectives: The aim of this study was to compare the effects of eight-week hamstring stretching programs, implemented at different times during physical education classes (i.e., warm-up, cool-down, and both periods), on primary schoolchildren’s back-saver sit-and-reach scores. Methods: A total of 275 schoolchildren (141 females and 134 males; age 8.82 ± 1.63 years) were divided into four groups: the WUG performed stretching during warm-up, the CDG during cool-down, and the MXG during both. The NSG followed the standard classes of physical education without any stretching. During physical education classes WUG, CDG, and MXG performed a 4 min stretching program twice a week. Hamstring extensibility was assessed before and after the program using the back-saver sit-and-reach test. Results: The CDG is the one that achieved statistically significant improvements compared with the WUG, MXG, and NSG (p ≤ 0.01; d = 0.50–0.71). Moreover, the CDG statistically increased the percentage of schoolchildren achieving healthy hamstring extensibility from pre-intervention (49%) to post-intervention (66%). Conclusions: This knowledge could guide teachers to design programs that guarantee feasible and effective development of hamstring extensibility in the physical education setting.