Improvement of Exercise Capacity after Bed Rest in Patients with Coronary Artery Disease: Role of Increased Thigh Muscle Mass Produced by Endurance Training

To assess the relation between the changes of exercise capacity and thigh muscle mass during 9 weeks exercise training in Twelve patients with coronary artery disease (61±4 years) who had been at bed rest for 3 weeks, symptom-limited incremental exercise tests in a ramp pattern on a cycle ergometer and computed tomography to evaluate plural cross-sectional areas of the thigh muscle in each limb were performed before and after training. Training resulted the increase in anaerobic threshold by 19±21% (p<0.05) and the increase in calculated thigh muscle mass by 11±7% (p<0.001). The ratio of the increase in oxygen uptake to the increase in work rate (Δ V^^･O_2/AWR) was not changed (8.46±0.83 vs. 8.63±0.74 ml/min/W, p=n.s.), suggesting that the degree of the oxygen delivery to working muscle during exercise might not be changed after training. The increase in anaerobic threshold was significantly correlated with the increase in calclated thigh muscle mass (r=0.65, p<0.05). Therefore, the increase of thigh muscle mass caused by exercise training might play an important role for the improvement of the exercise capacity after bed rest in patients with coronary artery disease.

運動療法

嫌気性代謝閾値

大腿筋肉量