Effects of a 6-Week Home-Based High- or Regular-Volume Static Stretching or Hamstring Resistance Exercise in Young...

Area of Science:

• Sports Medicine
• Biomechanics
• Exercise Physiology

Background:

• Hamstring tightness is common in young men.
• Understanding the effects of different stretching durations and exercise modalities on hamstring properties is crucial for optimizing training programs.

Purpose of the Study:

• To investigate the effects of unilateral long-duration static stretching (LS) on range of motion (ROM), musculotendinous unit (MTU) stiffness, muscle thickness (MT), strength, and contralateral effects (CE).
• To compare LS with typical-duration static stretching (SS) and hamstring resistance exercise (HRE) in young men with hamstring tightness.

Main Methods:

• Sixty-eight young men with hamstring tightness were randomized into four groups: LS, SS, HRE, or control.
• Assessments of ROM, MTU stiffness, MT, and knee-flexor peak torque were conducted at baseline, post-6-week intervention, and at 3-month follow-up.

Main Results:

• All exercise groups (LS, SS, HRE) showed improvements in ROM after 6 weeks.
• Both stretching groups experienced significant reductions in MTU stiffness.
• Reductions in MTU stiffness persisted in the LS group at the 3-month follow-up; no significant changes in muscle thickness were observed.

Conclusions:

• One hour of hamstring stretching did not yield superior improvements in ROM, MTU stiffness, or other adaptations compared to SS or HRE.
• Typical-duration static stretching (SS) is an effective and time-efficient method for improving hamstring flexibility and mechanical properties in a home-based setting.