New research examines the question of whether high-intensity exercise is beneficial for heart disease patients. The result:
“The four studies, which were composed of patients who either had acute coronary syndrome or angina pectoris, confirmed previous findings that high-intensity exercise is safe, even for patients with CHD” – quote is from this article High-Intensity Exercise for People With Heart Disease.
Another quote from the article:
"When we compared VO2max before and after the training period, we found that the number of training sessions, the subject's age or baseline fitness levels had no impact, but the intensity of the intervals had a significant effect, and seems to be the most important characteristic of an effective interval session.”