The Latin term argumentum ad nauseam refers to an argument that is repeated so many times that people will believe it, regardless of whether it's true or false. When it comes to exercising for fat loss, there are numerous myths that have been repeated so many times that people accept them as fact. As your local Physician Mythbuster, I hate to burst your bubble, but it's time to separate fantasy from reality.

A common fantasy among those trying to lose weight is that to lose the most weight, you need to exercise in your "fat-burning zone," which you reach when doing low- to moderate-intensity aerobic exercise.

The truth is that at low- to moderate-exercise intensities, you expend a higher percentage of your energy from fat. However, that does not mean you'll burn fat overall. In reality, you're in your "fat-burning zone" even when just sitting around, because at least 50 percent of the energy you burn while at rest comes from fat. As always, total energy expenditure is what really matters.

In fact, research indicates that it's better to work hard, not easy, when you want to lose body fat. In another study, subjects who did interval training—bursts of high-intensity aerobic activity—tended to lose more body fat than subjects who did steady aerobic exercise. Scientists have found that, even though you don't burn much fat during interval training, you expend a lot of energy and fat afterwards, even more than if you did aerobic training at a steady pace.

Give interval training a try and see what happens to your overall body-fat percentage.

Stay tuned and we will look at Fantasy No. 2: You shouldn't weight train when trying to lose weight, because it will make you "bulk up."