How Does Stretching Affect Reactive Strength?

Background on Stretching

Recent literature suggests performing traditional static stretching (SS) prior to exercise decreases strength and speed. Additionally, recent literature suggests performing dynamic stretching (DS) prior to exercise may be a better pre-exercise activity to improve in strength and speed during physical activity.

Moreover, the evidence that SS decreases muscle soreness is marginal and is irrelevant to injury prevention prior to exercise.

It is believed SS preceding exercise decreases the stretch-shortening cycle (SSC), an important variable in many sports.

The purpose of this study was to assess the effects of SS and DS on SSC performance in female field sports.

What was done

Fifteen division 1 soccer players and club rugby players participated in the study and on three separate occasions one week apart performed one of the three conditions after a 10-minute warm-up:
1. Warm-up only (WO)
2. SS: Four stretches targeted at the gluteus maximus, hamstrings, quadriceps, and gastrocnemius. Each stretch was performed three times for 30-seconds with a 10- second rest interval.
3. DS: Four dynamic stretches target the at the same muscle groups.

Following the assigned session, each subject performed drop jumps from 45 cm onto a force plate.

Results

The DS group had significantly greater relative strength index and flight time compared to the SS and WO groups.

Discussion

This study suggests that doing DS directly before a reactive movement improves relative strength and flight time compared to SS and WO. It was thought that the SS would impair performance compared to WO, secondary to impairments to the SSC, this hypothesis was not supported in this study.

Practical Implication

Once again, dynamic stretching prior to competition results in superior results compared to static stretching, suggesting its use prior to competition.