Can exercise cause weight gain?

I noticed I had put on a couple pounds recently even though I'd been exercising more. This puzzled me.

It seems this is somewhat natural in some people. Exercise should cause overweight people to lose weight. And it does, so long as your calorie intake is less than your calorie expenditure.

They say you lose one pound of fat for every 3500 calories you burn above your total calorie intake. This understanding is quite simpler than the weight loss commercials on TV.

However, why do I gain a few pounds?

Well, I have been eating more. My muscles have grown - it's not more fat that I have, it's more muscles!

One exercise physiologist says that is normal. Exercise has many benefits. It tones the muscles, makes them more efficient and gaining a few pounds of muscle is quite possible.