Chronic flexibility improvement after 12 week of stretching program utilizing the ACSM recommendations: hamstring...

Area of Science:

• Sports Medicine
• Exercise Physiology
• Biomechanics

Background:

• The American College of Sports Medicine (ACSM) recommends specific flexibility training parameters for improving joint range of motion.
• Limited evidence exists on the effectiveness of ACSM recommendations and optimal stretching parameters (technique, duration).
• Hip flexion range of motion (PROM) is crucial for functional movement and athletic performance.

Purpose of the Study:

• To investigate the effectiveness of ACSM flexibility training recommendations in improving hip flexion PROM.
• To compare the impact of different stretching techniques (passive vs. active) and single stretch durations (15, 30, 45 seconds) on hip flexion PROM.
• To evaluate the efficacy of ACSM-based flexibility training in recreationally active young adults.

Main Methods:

• A randomized controlled trial involving 173 recreationally active university students (122 males, 51 females).
• Participants were assigned to a control group (no stretching) or one of six stretching groups.
• Stretching groups followed ACSM guidelines for 12 weeks (180s total daily dose, 3 days/week) with varied techniques and durations; hip flexion PROM measured via bilateral straight-leg raise test.

Main Results:

• All stretching groups demonstrated significant improvements in hip flexion PROM compared to the control group.
• No significant differences in PROM improvement were observed between passive and active stretching techniques or varying single stretch durations (15, 30, 45s).
• The control group showed a decrease in PROM, while stretching groups exhibited an average increase of 15.14 degrees.

Conclusions:

• Current ACSM flexibility training recommendations are effective for enhancing hip flexion range of motion in young, active adults.
• The specific stretching technique and single stretch duration within the ACSM parameters do not significantly alter effectiveness for hip flexion.
• Consistent adherence to ACSM flexibility guidelines promotes significant gains in hip mobility.