Cardiovascular Risk of High- Versus Moderate-Intensity Aerobic Exercise in Coronary Heart Disease Patients
Background—Exercise performed at higher relative intensities has been found to elicit greater increase in aerobic capacity and greater cardioprotective effects than exercise at moderate intensities. It has also been detected an inverse association between the relative intensity of physical activity and the risk of developing coronary heart disease, independent of the total volume of physical activity. Despite that higher levels of physical activity is effective in reducing cardiovascular events, it is also advocated that vigorous exercise could acutely and transiently increase the risk of sudden cardiac death and myocardial infarction in susceptible persons. This issue may affect cardiac rehabilitation.
Methods and Results—We examined the risk of cardiovascular events during organized high-intensity interval exercise training and moderate-intensity training among 4846 CHD patients in four Norwegian cardiac rehabilitation centers. Of a total of 175 820 exercise training hours where all patient performed both types of training we found one fatal cardiac arrest during moderate-intensity exercise (129 456 exercise hours), and two non-fatal cardiac arrests during high-intensity interval exercise (46 364 exercise hours). There were no myocardial infarctions in the data material. As the number of high-intensity training hours was 36% of the number of moderate-intensity hours, the rates of complications to the number of patient-exercise hours were 1 per 129 456 of moderate-intensity exercise and 1 per 23 182 of high-intensity exercise .
Conclusions—The results of the current study indicate that the risk of a cardiovascular event is low after both high-intensity exercise and moderate-intensity exercise in a cardiovascular rehabilitation setting. Considering the significant cardiovascular adaptations associated with high-intensity exercise, such exercise should be considered among CHD patients.
- Received June 6, 2012.
- Accepted July 6, 2012.
- Copyright © 2012, American Heart Association, Inc. All rights reserved. Unauthorized use prohibited