Acute effects of resetting the stretching intensity on range of motion and passive stiffness in healthy adults: A randomized crossover trial

Introduction

Static stretching, a common method used to improve flexibility, has traditionally involved repeated stretching until reaching the initial or pre-determined stretching angle or torque. However, recent recommendations suggest that stretching until reaching a new maximal angle may offer greater benefits owing to increased stretching intensity. This study aimed to examine the acute effects of resetting the static stretching intensity on flexibility.

Methods

In this randomized crossover trial, 14 healthy participants performed 300-s of static stretching of the right hamstrings randomly under two conditions: resetting the stretching intensity at new maximal knee extension angles every 30 s (10 × 30-s) or no-resetting (1 × 300-s). The outcomes assessed included range of motion (ROM), passive torque (PT) at pain onset, passive stiffness before and after stretching, and stretching angle during stretching.

Results

During the 10 × 30-s condition, stretching angle was increased gradually (p < 0.05). Significant improvements were observed in ROM, PT at pain onset, and passive stiffness (p < 0.05) after stretching under both conditions. Moreover, the relative improvement in these parameters was greater under the 10 × 30-s condition than under the 1 × 300-s condition (p < 0.05).

Conclusion

These findings suggest that resetting stretching intensity can enhance flexibility, possibly due to the increased stretching intensity, underscoring the importance of individualized stretching approaches to optimize flexibility outcomes.