You could do cardio all day long and it still won't get rid of the fat if your diet is not in check. When I say all day long, I mean all day long. I belong to a cycling club and we typically ride few hours to a half a day and lot of guys in the group have a belly - some quite big. The reason is that they (and me too sometimes) eat donuts and brownies afterward or big meal thinking we burned off lots of calories. Yeah it suck but still diet is only way.