Walking, whether outside or indoors on a treadmill, is low impact, easy to do, and can provide excellent results for even those who are severely out of shape. However, there are ways to increase the results you get from your treadmill walking workout. As with any workout, you can step up the benefits of the workout by taking a slightly different approach. This is particularly helpful if you've been walking for a while and have hit a plateau, or if you're finding yourself bored by your walking workout. Plateaus are always frustrating, and changing the workout to include interval training can be just the thing to get you going again.

One of the best ways to increase the effectiveness of any workout, including a treadmill workout, is to use interval training. Although it's simple to do, the results can be profound.

The basics of interval training involve exercising at varying intensity throughout your workout. For example, start with a five-minute, light walk to warm up, then increase to a faster walk. From there, go to a fast walk or a jog, then back to a slower walk. Alternating speeds and intensity through the course of the workout helps your body burn more calories, provides a challenge to muscles, and alleviates boredom. For those pursuing weight loss, or training for a marathon walk or other long-distance event, interval training is a great way to challenge the body.

For a quick start in interval training on your treadmill, here are three ways to easily get this powered-up workout underway:

1. Vary speeds. If you can program your treadmill, use this feature to change the speed for short intervals. Don't forget to include the slower sections. The goal is to go from higher intensity to lower intensity over a period of time, not to consistently increase speeds.
2. Use your music collection. Put together a playlist with songs of varied tempos. Again, don't forget to alternate fast with slow. You don't want to do your entire workout to slow ballads, but you don't want to stick with fast power rock, either. This is a great way to vary your pace if you can't program the treadmill to do it for you.
3. Use hills and valleys. If your treadmill allows for increased resistance and different inclines, use these to produce a route that will put different demands on your body. Combined with different speeds, this approach will challenge even the most seasoned treadmill walker.

Whatever approach you decide to take, don't forget to take it slowly if you've never tried this kind of workout before. Your workout won't help much if you pull a hamstring or otherwise injure yourself right out of the gate. Also, be sure to consult your physician before starting or making major changes to a workout, particularly if you have any existing medical conditions that might affect your ability to walk for an extended amount of time.