Q. What is better for my heart—a fast run on the treadmill for 10 minutes or 30 minutes of light cycling on a machine?
A. The benefit of exercise on heart health depends on the dose; in other words, the more the better. So, my answer to your question is “Why not do both?” Exercise of virtually any kind prevents heart attacks, strokes, high blood pressure, and diabetes.
Most studies indicate this benefit begins at low levels of exercise, and increases with higher amounts of exercise. A good general goal is 150 minutes of moderate exercise per week. Moderate exercise is the equivalent of a brisk walk or speedy yard work—enough to increase your breathing rate and cause you to break a sweat.
But is faster even better? Proponents of high-intensity interval training recommend a maximum effort for short periods of time, with brief periods of rest. A common routine is one minute of high-intensity exercise, followed by two minutes of walking, and then repeating this several times.
Although it is true that the energy expended in a short burst of activity is equivalent to a longer period of moderate exercise, the long-term health benefits of high-intensity exercise have not been clearly demonstrated. In addition, it raises concerns about physical injuries from high-intensity training if the individual has not been regularly exercising.
So, aim for the equivalent of 150 minutes of moderate exercise per week, or 60 to 75 minutes of more vigorous exercise. You can vary your exercise regimen and mix both types to keep things interesting and enjoyable.
— William Kormos, M.D.
Editor in Chief, Harvard Men’s Health Watch