If I do a lot of crunches, will I burn a lot of belly fat? Let me think about that for a bit... Nope. Crunches don't burn belly fat. OK, they burn a bit of fat. Talking burns fat too, just not as much as you would want to if you're trying to slim down. Unfortunately. Or not, since I know some people who would be 4 inches around if it did.

Anyway, back to crunches. Some people think if they do crunches the fat on their belly will magically disappear and the fat other places won't be touched. But the fact is, you can't spot reduce fat. Your body decides where to put the fat, and where to burn it. It depends on your genetics.

So why don't crunches burn much fat, since it's so hard to do them? You might do a hundred crunches and your abs are burning like crazy. But you still haven't burned many calories - maybe about a hundred.

It's because your ab muscles are so small. Think of two cars: a Bugatti Veyron with an 8 L engine, and a Smart car with a 0.8 L engine. Which will burn more gas? The Bugatti, of course, because its engine is bigger and more powerful. It's the same with muscles; bigger ones (legs) use more energy than smaller ones (abs, biceps).

Another thing: you can probably only do crunches for a few minutes or less. But take some sort of cardio, like football: you might be able to play football for an hour or longer. Which will burn more fat: an hour of football or a few minutes of crunches?

Instead of crunches for fat loss, try a better way: moderate or high intensity cardio. You can even try intervals - go all out for a certain time and then rest for a certain time. That way you could do more easily do 15 minutes of hard, fat-sizzling work. It will raise your metabolism as well, so you'll burn more energy even when you're resting.

Another way to lose weight is to lift weights: relatively heavy compound movements will build muscle (which burns extra calories) and also burns calories while your body recovers from it - for up to 24 or even 48 hours.

But all this won't do much if your diet is bad. Lots of junk food, pop, and processed foods could prevent fat loss no matter how much exercise you do. It's pretty obvious that diet is a big deal, but surprisingly it's something that a lot of people don't think twice about.

If you still want to do crunches to lose weight, go ahead - maybe 500 a day will help a little bit. But probably not, since you'll build a layer of muscle under the belly fat. And you probably won't use enough energy to get rid of the fat. Oops.

So really, although you don't have to cut out crunches altogether, just try to focus on other ways to lose fat - do some weight lifting and cardio for that.