Short, Intense Workouts Improve Fitness and Health

by Dr. Gabe Mirkin, M.D.

How intense can you go? (image from: T-nation.com)

Don’t complain that you do not have enough time to gain the health benefits of exercise. A new study shows that forty minutes of intense exercise, three times a week for 10 weeks:

• increases VO2max,
• lowers blood pressure,
• lowers blood sugar levels,
• reduce body fat, and
• lowers total cholesterol, the bad low-density lipoprotein (LDL) cholesterol, and the oxidized LDL cholesterol that forms plaques in arteries. (PLOS One, June 4, 2013).

VO2max measures the maximal ability to take in and use oxygen. It is a measure of fitness level that also predicts how long a person is likely to live (Med Sci Sports Exerc 1999;31: S646–662).

The Study's Training Protocol

In this study, men who had not exercised for at least two years, and did not have heart or lung disease, exercised on an inclined treadmill three times a week. They took:

1. a 10-minute warm up at 70 percent of their maximum heart rate followed by
2. four sets of four minutes each, of jogging at 90 percent of maximum heart rate, followed by three minutes of active recovery at 70 percent maximum heart rate followed by
3. a five-minute cool-down

Total exercise time for each session was 40 minutes. At 90 percent of maximum heart rate, a person gasps for breath and cannot carry on a conversation.

Intense Exercise Provides Increased Health Benefits

Athletes learn that they cannot compete effectively unless they train at a level at or near their maximal intensity. To do this, most athletes use a technique called interval training. They exercise at near their maximum intensity for a short time and become very short of breath. They recover their breath by slowing down for a short period, and then go as hard as they can again. They repeat these intervals until their muscles start to hurt and feel stiff. The next day they are sore and train at a much slower pace.

Many recent research papers show that the interval training technique used by athletes can provide health benefits that would take far longer to achieve with training at a lower intensity. This new study shows that people can use very intense exercise to become fit and improve their health in as little as 40 minutes three times a week. Interval training will strengthen your heart far more than less-intense training. Caution: People who already have blocked arteries leading to their hearts need to be cautious with interval training because their hearts may not be strong enough to tolerate the extra work of intense training. Therefore, you should probably check with your doctor before starting intense interval training.