Effects of Aerobic Cycling Training on O₂ Dynamics in Several Leg Muscles in Early Post-myocardial Infarction

The aim of this study was to test the effects of aerobic cycling training on O₂ dynamics in several leg muscles in early post-myocardial infarction (post-MI). Fifteen post-MI patients were divided into a 12-week training group (TR, n = 9) or a control/non-training group (CON, n = 6). All participants performed ramp bicycle exercise until exhaustion at two times: within 12-35 days of their MI and then again 12 weeks later. Muscle O₂ saturation (SmO₂) and total hemoglobin concentration (∆total-Hb) were monitored continuously at thigh and lower leg muscles by near infrared spectroscopy. In CON, there were no significant alterations in muscle O₂ dynamics between before and after 12 weeks at any measurement sites. In TR, after 12 weeks, lower SmO₂ was observed at all measurement sites. In total-Hb, no significant changes were found after training at any measurement sites in TR. Moreover, the muscle deoxygenation after 12 weeks was related to an improvement of peak O₂ uptake in all muscles. Our findings suggest that aerobic cycling training may be useful for early post-MI patients to improve peak aerobic capacity via enhancement of muscle deoxygenation and O₂ extraction at several leg muscles.