Effects of flexibility training on eccentric exercise-induced muscle damage

Area of Science:

• Exercise Physiology
• Sports Science
• Muscle Physiology

Background:

• Eccentric exercise is known to induce significant muscle damage.
• Understanding protective mechanisms against exercise-induced muscle damage is crucial for athletes and researchers.
• Flexibility training's role in mitigating this damage requires further investigation.

Purpose of the Study:

• To investigate if flexibility training can attenuate muscle damage caused by maximal eccentric exercise.
• To compare the effects of static stretching (SS) and proprioceptive neuromuscular facilitation (PNF) on muscle damage markers.

Main Methods:

• Thirty untrained men were divided into SS, PNF, or control groups.
• SS and PNF groups underwent 8 weeks of specific stretching protocols.
• All groups performed maximal eccentric knee flexor contractions, with muscle damage markers assessed pre- and post-exercise.

Main Results:

• Both SS and PNF significantly increased range of motion (ROM) and altered knee flexor optimum angle.
• Compared to controls, SS and PNF groups exhibited less strength loss and faster recovery.
• Reduced muscle soreness and lower plasma creatine kinase and myoglobin levels were observed in SS and PNF groups.

Conclusions:

• Static stretching and PNF training are effective in attenuating eccentric exercise-induced muscle damage.
• Increased muscle flexibility appears to confer resistance to exercise-induced muscle damage.
• Flexible muscles are less susceptible to damage from strenuous eccentric contractions.