Well if you take into consideration that the muscles are made of red and white tissues, and that both types of tissue have different jobs to do, then you can start working on what to give to build them up. I must admit I use supplements, I give catasol, or red cell depending on what I'm trying to do, catasol is an injectable that gives a boost, so is good if the dogs had a hard time of it. I also feed fats (day before planned dig) that slowly release energy, so on long digs the dog has plenty on board to keep it going, and I use a supplement that helps to stop the lactic acid build up, as this