stationary bicycleIntense bursts of exercise may be as good for the heart as longer, moderate-intensity training. (Lynn L. Walters for The New York Times)

Short bursts of exercise can benefit heart health just as much as tedious endurance training, a new study suggests.

The research, published in the American Journal of Physiology — Regulatory, Integrative and Comparative Physiology, is good news for time-strapped exercisers. It supports the notion that people who engage in brief, high-intensity forms of exercise reap the same cardiovascular health benefits as those who exercise at moderate intensity for a longer period of time.

Researchers at McMaster University in Canada recruited 20 healthy men and women whose average age was 23. All of the study subjects rode stationary bikes. Some exercised five days a week, doing 40 to 60 minutes of moderate-intensity cycling. Others did four to six sets of 30-second sprints on the cycle, allowing 4.5 minutes of recovery time between sets; their total exercise time was about 15 to 25 minutes just three days a week.

After six weeks, the researchers found that the intense sprint interval training improved the structure and function of arteries as much as traditional, longer endurance exercise.

“More and more, professional organizations are recommending interval training during rehabilitation from diseases like chronic obstructive pulmonary disease, peripheral artery disease and cardiovascular disease,'’ said Maureen MacDonald, academic advisor and an associate professor in the department of kinesiology. “Our research certainly provides evidence that this type of exercise training is as effective as traditional moderate-intensity training. We wouldn’t be surprised to see more rehabilitation programs adopt this method of training since it is often better tolerated in diseased populations”.

The data don’t mean everyone should give up endurance training. Some people prefer moderate exercise, and for some, high-intensity intervals like sprinting are too demanding and may increase the risk of injury.

But Dr. MacDonald notes that those who have a hard time scheduling exercise into their lives can still get the benefits of exercise if they are willing to work hard for brief periods of time.