Walk-running is a fun and effective variation on a straight walking program, but bear this thought in mind: You never have to run a step to get a great workout, especially if running doesn't suit your body or personality. Walk-running is simply one way -- but not the only way -- to increase exercise intensity. If it appeals to you, go for it. If it doesn't, don't feel as if you are settling for second best. You can do very fast walking or uphill walking instead of running intervals and get a similar workout.

Post your questions and comments on the Tone Up Your Body message board!