Interval Training Can Spice Up a Workout When it comes to
fitness, a lot of people think the only way to improve is to do
more, more, more. But one way to enhance your workout makes do
with "less": interval training. Interval training alternates
short bursts of intense activity with periods of "active
recovery," which means more moderate forms of that same
activity. Elite athletes use the technique to improve their
speed, endurance, and overall fitness. But moderate or beginning
exercisers can use the same trick to burn more calories, improve
cardiovascular endurance, and get a bracing workout in a
relatively short time. How it works Interval training draws on
the body's two forms of energy production: aerobic and
anaerobic. In the aerobic state, the body uses oxygen to convert
stored carbohydrates into energy. This is the method you use
while walking, jogging, riding a bike, or even playing a
leisurely game of golf. If you keep working aerobically long
enough, or make more strenuous demands, such as sprintin