Metabolic contributions to hamstring muscle damage during maximal, high-speed eccentric exercise in males

Area of Science:

• Exercise Physiology
• Muscle Physiology
• Sports Science

Background:

• High-velocity eccentric training causes exercise-induced muscle damage (EIMD), primarily linked to mechanical strain.
• The role of metabolic stress in EIMD, particularly in trained individuals, is not well understood.

Purpose of the Study:

• To investigate the contribution of metabolic changes to EIMD during maximal eccentric hamstring curls.
• To explore the relationship between metabolic markers and muscle damage indicators in trained athletes.

Main Methods:

• Thirty trained males performed maximal eccentric leg curls at high velocity.
• Muscle oxygenation (SmO₂), gas exchange (VO₂, VCO₂), and various muscle damage markers were measured.
• Linear mixed models analyzed associations between metabolic parameters and damage markers.

Main Results:

• Peak torque decreased significantly post-exercise, and creatine kinase (CK) peaked at 96 hours.
• Increased oxygen uptake (VO₂) during rest intervals predicted lower CK elevations.
• Higher aerobic demands within sets correlated with greater force deficits, while SmO₂ changes did not significantly impact EIMD.

Conclusions:

• Metabolic factors significantly contribute to EIMD in high-velocity eccentric exercise protocols.
• Aerobic demands and recovery oxygen uptake influence muscle damage and recovery.
• Enhancing aerobic capacity may be crucial for mitigating muscle damage and improving recovery in demanding training.