Millions of people go to the gym week after week to do long, boring aerobic exercises that deliver little or no improvement in their physical condition. They spend up to an hour each night simply pacing on a treadmill or leisurely pedaling away on a stationary bike, yet they hardly break a sweat, and they rarely lose weight.

If this sounds like you, it’s time for the “20-Minute Aerobics Solution,” designed by Bill Phillips, author of the No. 1 New York Times bestseller Body for Life.

Phillips recommends 20 minutes of aerobic exercise only three times a week* rather than spending hour after hour, week after week, doing long, unfocused aerobic workouts.The challenge of the “20-Minute Aerobics Solution” is “to make each of those workouts the most effective, fat-burning, health-enhancing 20 minutes you possibly can.” To do this, Phillips provides readers with an intensity index.

The index starts at level one and goes up to level 10. Level one intensity can be achieved while doing such activities as sitting on the couch watching television, level two while standing, level five while walking up stairs, and so on. Level 10 is the highest point of intensity for the body. At this level, you should be able to honestly answer “No!” if asked “Can you go just a little bit harder?”

The intensity index is self-regulating, so levels differ for each individual depending on the individual’s condition and prior aerobic experience. As the body adapts to each workout, the intensity index should evolve with it. This program assures that an individual can never outgrow his or her own intensity index.

Phillips does not expect his readers to reach their high points during every workout. However, the high point is always the goal, making each and every workout a new challenge. Stationary bikes, treadmills, outdoor runs, and even walks work fine for aerobic exercises.

Phillips suggests the following interval pattern to make aerobic exercises more effective:
• Level five intensity for minutes one and two.
• Level six intensity for minute three.
• Level seven intensity for minute four.
• Level eight intensity for minute five.
• Level nine intensity for minute six.

Repeat this pattern three times to the end of minute 18. For minute 19, try to reach an intensity level of 10. Finish the workout at an intensity level of five for minute 20, and you will have completed the “20-Minute Aerobics Solution.”

* Some personal trainers recommend a minimum of four aerobic workouts each week rather than three. This workout pushes the body to its limit, so three aerobic workouts per week may be one body’s limit, while more than three workouts a week could be the limit for others. One day of easy aerobic exercise could fill in for the fourth day for each week.