Summer Shape-up

Summer's a time to strut your stuff. But some of us have more stuff than strut. Not everyone cares that summer garb unveils those flabby inner thighs, saggy underarms, loose guts and love handles.

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But if you do, you're probably heading for the gym. After all, with enough sweat and determination, you can whip that flab into shape, right? Wrong.

You can't make any area of your body smaller by working out that particular area. It doesn't work that way. It's two different tissues. Fat doesn't turn into muscle and muscle doesn't turn into fat.

Fat is stored in special cells called adipocytes that swell when you feed them more calories than you use. They're located all over the body, and depending on your genes, you have anywhere from 25 billion to 275 billion of them. Most of us average around 30-35 billion. Exercise stimulates adipocytes to release the stored fat, and while it would be nice to say burn it off my gut and thighs, please, unfortunately, that's not always the first to go.

Usually it's in the upper body, the arms, the neck, the shoulders. And then it's the ankles and lower leg first.

And unfortunately for many of us, it's often fat in the abs, hips, thighs, and buttocks that leaves last, if it leaves at all. So what to do?

If you want to lose weight, you probably want to do cardiovascular exercise 4-5 times a week, I'd say, for at least 30 minutes. And you want to work every muscle group in your body once a week to fatigue. And you also want to have a healthy diet.

Aerobic exercise encourages our fat cells to release lots of fat. Choose what motivates you—jogging, swimming, cycling, one of the cardio machines at the gym or an exercise class. Interval training is a great choice for fat burn. The combination of high intensity and low intensity exercise stimulates and speeds up the metabolism.

It's the best way to get the maximum amount of benefit in the least amount of time, because you're going to get your cardiovascular exercise at the same time that you're gonna get your weight training.

Weight training is key because it's a super way to speed up the metabolism. Muscle burns more calories than fat, and jumpstarts your metabolism for hours after you've finished your workout.

The more muscle you have the more calories you burn, even at rest.

Of course, none of this will do much good if you don't watch your weight. For help with that, visit our Weight Loss 101 video series.

: I'm going to take this container and put half my meal in it before I even get started.

For WebMD, I'm Sandee LaMotte.