Meant to educate and enlighten us, fitness research has had the unfortunate consequence of fueling many misperceptions about exercise. When data captures the attention of the media but is misinterpreted or inadequately explained, myths often proliferate until they assume a life and "truth" of their own.
The preoccupation in the United States with fat loss has triggered one such "myth-conception": exercising at a lower intensity will burn more fat. The truth is that low-intensity exercise burns a higher percentage of fat, which doesn't necessarily translate into a greater amount of fat. For example, exercising at a low intensity for 60 minutes may burn a total of 300 calories with 50 percent, or 150 calories, coming from fat. Exercising at a higher intensity for the same amount of time, however, burns 600 calories with 40 percent, or 240 calories, coming from fat.
"Even though a smaller percentage of the calories burned during high-intensity exercise comes from fat, the overall number of fat calories is greater than with low-intensity exercise," explains Jeff Zwiefel, director of the National Exercise for Life Institute. "This allows for more efficient weight loss."
Still more research coming from Georgia State University demonstrates that it's not the type of fuel you burn that's important, but the amount. Regardless of whether your body burns carbohydrate or fat during exercise, if you expend more calories than you consume over an extended period, your body will start relying on its stores of fat to get you through your regular daily activities. In the end, you still achieve the desired result -- fat/weight loss.
A word of caution. Although low-intensity exercise may not burn more fat, it's still a good choice if you're new to exercise, if you have physical restrictions (such as a heart condition), or if you want to give your body time to rest and repair between high-intensity workouts.
The following aerobic dance exercise can be performed at a low or high intensity for a fun, calorie-burning workout.
Begin with your legs together, knees bent, and your arms out to your sides and held low, as shown in photo at left. Hop off both feet and shift your weight to your left, finishing in a lunge to your left side (left knee bent and right leg extended to your right) while reaching your arms to the left.
Hop off your left leg, bringing both feet together in the center. Repeat to the right side, and continue alternating sides for a total of 16 repetitions. Two or three sets of these lunges can be sequenced to a favorite song with sets of other aerobic dance moves.