Skeletal muscle response to exercise training in congestive heart failure

Area of Science:

• Exercise Physiology
• Cardiovascular Health
• Skeletal Muscle Adaptation

Background:

• Congestive heart failure (CHF) patients often exhibit skeletal muscle dysfunction.
• Peripheral muscle abnormalities contribute to exercise intolerance in CHF.
• The potential for peripheral muscle adaptation to exercise in CHF remains under investigation.

Purpose of the Study:

• To investigate the adaptive capacity of skeletal muscle in CHF patients.
• To determine if localized exercise training improves muscle bioenergetics and function.
• To assess the impact of training independent of central cardiovascular changes.

Main Methods:

• Five CHF patients underwent 28 days of localized wrist flexor training.
• Magnetic resonance spectroscopy monitored muscle inorganic phosphate (Pi) and phosphocreatine (PCr).
• Muscle mass, endurance, limb blood flow, and bioenergetics were assessed before and after training.

Main Results:

• Muscle bioenergetics improved in the trained forearm, indicated by changes in the Pi/PCr ratio.
• Forearm muscle endurance increased by over 260% post-training.
• Muscle mass, limb blood flow, and pH remained unchanged; no systemic cardiovascular changes were observed.

Conclusions:

• Localized exercise training enhances muscle energetics and endurance in CHF patients.
• Improvements are specific to the trained muscle and independent of muscle mass or blood flow.
• Peripheral muscle adaptations can occur in CHF without altering central cardiac performance.