With light weights, I wouldn’t have been able to grow and hold on to muscle. When I began to learn the truth about how to get ripped and stay ripped, I came to understand that increasing lean mass is one of the keys to managing fat storage (besides the fact that lean mass makes you look good). The body stores its most usable forms of energy as either fat or glycogen. When carbohydrates are consumed they’re converted to glucose, which can be used for immediate energy. But when more glucose is present than is required to meet immediate energy needs, it’s converted by the liver into glycogen, which is essentially a chain (polysaccharide) of glucose molecules. The liver and muscles are glycogen’s primary storage vessels. Some glycogen manufactured by the liver is stored there, while the rest is transported into muscle cells by insulin. But if muscle glycogen stores are already maxed out, the glucose that would have been converted to glycogen is instead converted to triglyceride and stored as fat. The point here is that the more muscle a person carries, the greater the glycogen storage potential and the less likely it is that glucose will be converted to fat.
Well, not completely fasted.
If you haven’t read this page on intermittent fasting yet, you might want to consider doing that first.
There’s actually a caveat here: I did take BCAAs before, during and after lifting; the LeanGains founder is a proponent of it, and based on my own experience, I agree. There’s a sizable body of evidence detailing how and why BCAAs help maintain an anabolic environment (i.e. one that is conducive to protein synthesis). The reason for consuming BCAAs and not, say, whey, is because BCAAs are cited as the amino acids that are most effective in promoting muscle growth (specifically leucine), meaning that BCAAs should have greater efficacy per calorie than whey. Additionally, whey spikes insulin pretty significantly, which can create a hunger response. BCAAs spike insulin as well, but since far less BCAA is required to create the same protein synthesis response as literally quintuple the amount of whey, less insulin is released overall = reduced stimulation of hunger. It is also worth noting that because BCAAs are not classified as a nutrient by the FDA, companies that produce them are not required to include caloric data on the label. However, BCAAs do contain four calories per gram (same as any other protein). To get 10g BCAA you either have to consume, say, 12g of BCAA powder (actually, it varies depending on the brand/ concentration) or 60g of whey. That’s 48 calories vs 240 calories to elicit the same anabolic response.
The fasting piece goes back to the LeanGains protocol. Several medical studies conducted over the past two decades have indicated that insulin can blunt the release of growth hormone (http://www.ncbi.nlm.nih.gov/pubmed/10484056). Theoretically, maintaining low circulating insulin levels would provide an environment most conducive to the release growth hormone, providing that the stimulus applied to muscle is sufficient (i.e. lifting heavy). When insulin is reintroduced (after eating) in the presence of growth hormone, its effects are amplified. While I cannot say whether or not this is totally true, I still think intermittent fasting has been so incredibly helpful for me predominantly because it is a great tool for caloric control.