Doreen,

For those who lose weight primarily because of exercise, you lose weight from heat production, .... fats, sugars and carbohydrates are "burned" just like fuel in your car to produce energy. The by-products of this combustion are then expelled by respiration and perspiration. (Water and carbon dioxide)

However, the "bulk" of your weight loss, literally goes down the toilet!!

So "flush " out all that unwanted fat!!

Ken