Post by @liftrunbang

This new calculation paper just put an actual number on the energetic cost of building human skeletal muscle. Researchers broke down the full cost of creating 1 kg (2.2 lb) of wet skeletal muscle from first principles. Their central estimate: roughly 3,480 extra calories of metabolizable energy needed to build and maintain that kilo of muscle. Spread over a realistic 12-week period, that works out to only about 41 calories per day. For 2 pounds of muscle over the same timeframe, you’re looking at roughly 37–40 extra calories a day. That number is not just the energy required for peptide bond formation, transcription, translation, and protein folding. Those direct biochemical synthesis costs are actually pretty small . At only around 160 calories per kilo of muscle. The bulk of the cost comes from several other layers: • The chemical energy that ends up stored in the new tissue itself (protein, a little fat, and glycogen) • The inefficiency of actually depositing that tissue in a living adult human (protein deposition is only about 42–52% efficient) • The energy required to keep the newly accumulating muscle alive while it’s being built (part of your BMR) • The thermic effect of the extra food needed to cover all of the above When you add everything up and convert it into extra food energy you need to eat, you land at that 3,480 kcal per kg figure. Important context: this is strictly the cost of the muscle tissue itself. It does not include the energy burned during the training sessions, recovery processes, connective tissue remodeling, or any other systemic costs of training. It shows what I've been saying for quite some time. That the pure energetic price of adding muscle is surprisingly low once you isolate it. And this why shooting for maintenance calories is a far safer bet than shooting for a surplus when all the current research shows that surpluses just increase fat gain