Resistance Exercise Training Alters Mitochondrial Function in Human Skeletal Muscle.

Area of Science:

• Exercise Physiology
• Mitochondrial Biology
• Skeletal Muscle Adaptation

Background:

• Mitochondrial dysfunction is linked to chronic diseases, necessitating strategies to enhance mitochondrial health.
• Endurance exercise is known to improve skeletal muscle mitochondrial function, but the effects of resistance exercise training (RET) are less understood.

Purpose of the Study:

• To investigate the impact of a 12-week RET program on the respiratory capacity and overall function of skeletal muscle mitochondria.

Main Methods:

• 11 healthy young men underwent a 12-week RET program.
• Skeletal muscle biopsies were analyzed before and after training using high-resolution respirometry in permeabilized myofibers.

Main Results:

• RET increased lean body mass and muscle strength.
• Coupled mitochondrial respiration supported by Complex I and Complex I+II substrates significantly increased.
• Complex I protein abundance rose, while substrate control ratio for succinate decreased, indicating enhanced mitochondrial efficiency.

Conclusions:

• Twelve weeks of RET induces significant qualitative and quantitative improvements in skeletal muscle mitochondrial respiration.
• These adaptations involve modest changes in mitochondrial protein and transcript expression.
• RET is a viable strategy to augment the respiratory capacity and intrinsic function of skeletal muscle mitochondria.