Q: What is the effect of AAS on burning fat? I know that AAS increase your resting metabolic rate (a necessary condition of increased anabolism). But is that all? That wouldn’t do much at all to burn fat, simply because (as I understand it) there is no good evidence that our bodies burn fat for the purpose of building muscle. Rather, fat is burned for immediate energy needs (work we perform), while muscle growth is dependent on daily food intake. Moreover, if you’re eating enough food to put on serious muscle mass, you’re eating enough that you’re probably gaining a little fat, too. But, I thought I had read that fat cells also have androgen receptors, and that taking AAS stimulated fat cells to release their energy stores. Is that a real fact, or did I just make that shit up?
Bill Roberts’ answer: You’re right, there are androgen receptors in adipocytes and androgens do have effects on them.
However, stimulating lipolysis can only ever be part of the equation, and by itself is not sufficient. Releasing more fatty acids into the bloodstream doesn’t result in them now being excreted from the body, but either they are burned or they are reabsorbed.
So if calories burned does not increase, fat loss does not increase.
However, increased availability of fatty acids is one of the factors that tends to increase metabolic rate. And sluggish lipolysis combined with low caloric intake results in depressed metabolism. So I am not dismissing the value of increased lipolysis but only saying that increased energy expenditure, whether from increased RMR or increased activity, must occur for this to lead to fat loss benefit.