Gesel, Francis J.; Morenz, Emily K.; Cleary, Christopher J.; LaRoche, Dain P.

Journal of Strength and Conditioning Research: August 2022 - Volume 36 - Issue 8 - p 2147-2155, doi: 10.1519/JSC.0000000000003894

PURPOSE:

To evaluate the effects of static and ballistic stretching on muscle-tendon unit (MTU) stiffness, work absorption (WA), strength, power, and counter movement vertical jump (CMJ) performance.

PROCEDURES:

22 subjects performed 3 separate experimental conditions for the quadriceps, hamstrings, gluteus, and plantar-flexor muscles:

1. No-stretching.

2. Ballistic stretching.

3. Static stretching.

After each condition plantar-flexor MTU stiffness, WA, isometric strength, and power were measured, followed by a CMJ on a force plate to obtain peak center of mass velocity, peak power, rate of force development, peak force, work, and vertical jump height.

CONCLUSIONS:

An acute bout of static stretching significantly reduced WA by 12% and isokinetic power by 8% as compared with the control condition but ballistic stretching did not.

Significant positive correlations existed between MTU stiffness, WA, strength, and power. Despite significant positive correlations between MTU stiffness, WA, and CMJ performance measures, neither static nor ballistic stretching affected CMJ performance.

IN PLAIN ENGLISH:

Stiffer MTUs absorb more work (energy) and are associated with greater muscle force, power, and CMJ performance.

Performing an acute bout of static stretching impairs MTU passive-elastic properties and power production but it – along with ballistic stretching – does not impair isometric strength or CMJ performance.

So, to stretch or not to stretch? Looks like it can go either way.