If a body-builder
Very hard for exercise
to increase weight unless one is a body-builder. Exercise burns
calories, so if one does not eat or drink more calories than he is using during his exercise, then his body will burn up fat as fuel.
However, if a person drinks a large orange juice (about 300 calories) while exercising, and exercises away only 200 calories, he will still get fatter even though he's exercising.