Work

Endurance exercise induces distinct skeletal and cardiac mitochondrial adaptations in racehorses

Year: 2026

Type: article

Abstract: This study reveals how endurance training shapes mitochondrial function in the heart and skeletal muscle. Using racehorses as a natural large-animal model, we compared mitochondrial respiration across all four cardiac chambers and skeletal muscle. Skeletal muscle mitochondria from trained horses showed greater respiratory capacity, whereas cardiac mitochondria did not. These findings uncover tissue-specific metabolic adaptations to exercise and highlight how cardiac energetics may influence susceptibility to atrial fibrillation in endurance athletes.

Source: American Journal of Physiology-Heart and Circulatory Physiology

DOI: 10.1152/ajpheart.00833.2025