you need to realize how you will be gaining weight...if you are looking to lose fat then keep up the cardiovascular exercise, but taking a nitric oxide-based product will not make you gain any weight from fat. It will simply enhance your workouts to where you are building more muscle which is heavier than fat. So yes if you are not burning off fat then you will be gaining a lot of weight in muscle, but if you are losing body fat while adding muscle weight then you won't see a huge increase in weight (just a minor increase because muscle is heavier than fat)