For some people looking to drop a significant amount of weight, strapping on a pair of running shoes just may not be an option. But that doesn't mean you can't hit the treadmill for a good cardio session anyway. If a run hurts your back too much or you lose your breath too quickly, try burning calories by walking. Nicki Anderson, president of Reality Fitness and author of Nicki Anderson's Single-Step Weight Loss Solution, tells you how.
If you decide to join a gym, commit to walking three to five days per week for 20 minutes per session. Once that's easy, step it up. Think in tens—a 10% increase in the amount of time you're walking or a 10% increase in your incline or speed. To keep from getting bored, set goals. If it normally takes you 20 minutes to cover a mile, aim for 18 minutes in your next session.
If you'd rather start outside, you should still plan on walking three to five days per week for at least 20 minutes. Begin at your regular pace. When you're ready to go harder, look for a marker (a fire hydrant or a stop sign) 40 yards ahead of you and walk as fast as you can until you hit it. Then return to your regular speed. Repeat every couple of minutes so you can slowly build up your conditioning level. Basically, it's beginner level interval training.
Keep walking regularly until you can clear three miles in less than 45 to 60 minutes. Once you can do that, you should be ready to move on to running.