It's hardly news that exercise is good for you -- we know that it can help keep weight off, build a bigger brain, improve mood and lower the risk for cancer and heart disease. But many people continue to put off the idea of exercise because of time constraints, even with news like this: High-intensity exercise for brief periods of time may help reduce the risk of diabetes.

A new study demonstrates -- as I've argued for years -- that you don't have to spend an hour in the gym or on the track in order to get the significant health benefits that exercise has to offer. In the study, researchers had young healthy male volunteers use exercise bikes to perform quick, rigorous 30-second sprints, Over the course of two weeks, the subjects performed 30 of these sprints (about two or three a day) for a grand total of 15 minutes total exercise. You read that right: 15 minutes. Over the course of two weeks. And the researchers found that this low-volume high-intensity training substantially improved the body's ability to process sugar.