For what it's worth, in my own experience as someone prone to adding extra weight, any added weight you put on can be easily shed and is probably mostly water. It's only after the fats have been there, immobile, for several weeks that losing it becomes a problem. Remember, just because you're not working out that day doesn't mean your body is a rest. It's burning fuel- recuperating from the day before, and gearing up for your next work out. Also, the juice is still in your system- you might as well take the advantage. No sense going overboard, but as I found out, you still have to EAT BIG TO GET BIG.