Guest Post by Dr. Gabe Mirkin

To be competitive, all athletes must train very intensely some of the time. New research from McMaster University in Canada shows that short term, high-intensity interval training on a bike can also provide you with all the health and fitness benefits of exercising less intensely for a much longer period of time (The Journal of Physiology, March 2010). Subjects used a standard stationary bicycle and performed a workout of ten 1-minute sprints with a 1-minute rest between each at 95 percent of their maximal heart rate, three times a week. This takes less effort than an all-out sprint at close to 100 percent of maximal heart rate. The study supports other research that shows that high-intensity training improves speed and endurance far more than long slow distance and is necessary for training for athletic competition.

The same authors showed that a similar short workout of all-out sprinting at maximal heart rate took about 90 minutes per week (three workouts of 30 minutes each) and was as effective in achieving fitness and health benefits as many hours of exercising at a much more leisurely pace (The Journal of Physiology, September 2006). High intensity, short-interval training improves fuel and oxygen delivery to muscles, helps the removal of waste products, and increases the number and efficiency of mitochondria that help muscles use oxygen to burn food for energy. These changes have been shown to reduce risk for heart attacks, strokes, diabetes, weight gain and even some cancers.

The authors make no mention of alternating intense stress and low-intensity recovery workouts, in which you spend more than 80 percent of your exercise time going at a very low intensity. Training intensely without recovery workouts markedly increases your chances of injuring yourself.

High-intensity training can cause heart attacks in people with blocked arteries and muscle injuries in anyone. Before starting, a) check with your doctor to make sure your coronary arteries are open and b) you should be able to pedal on a stationary bicycle slowly for at least an hour a day for several weeks. A program of high-intensity intervals:

• will improve speed and endurance much more than slow long- distance workouts

• should not be done when muscles feel sore or you feel sick because it increases your chances of injuring yourself

• should be part of a “stress and recover” program in which you go intensely never more often than three times a week and spend far more time exercising less intensely.

High-intensity interval training causes muscle burning and severe shortness of breath, so don’t do it unless you enjoy the thrill of competition.

Dr. Mirkin is a sports medicine doctor, fitness guru, and long-time radio host.  Check out his website at