What it is: A more challenging walk that alternate between hard and easy periods of work.
Why it's good for you: If time is your biggest enemy, interval training is perfect for you. "Incorporating intervals into your workout can shorten your total exercise time and get you fitter faster," says Jason Talanian, Ph.D., professor of exercise science at Bacone College in Muskogee, Oklahoma.
What research says about it: In one of Dixon's studies, women who did interval training improved overall health and their body's fat-burning potential in as little as two weeks. Not only do you burn calories during the workout, you also burn more just doing everyday things after an interval training walk, Dixon says.
Who should do it: Walkers who want to get in shape in less time or bust a plateau. Do two or three weeks of endurance first.
How often you should do it: Once or twice a week on nonconsecutive days.
How to do it: Warm up with an easy five-minute walk. Then alternate between one to four minutes of moderate-paced walking and one to four minutes of brisk or fast walking, repeating this pattern two to five times during your walk. During the brisk/fast walking sections it should feel as if you're working hard, and talking becomes more difficult.