For some reason, many bodybuilders believe they have to turn themselves into a giant pumpkin during the off season in order to build any muscle. They believe, “you can't grow muscle when you're dieting.” Oh my God..... To find a greater pile of bullshit than that you'd have to visit a cattle ranch. That is such utter nonsense. It's true that you could not eat enough on a diet and not gain muscle, but it's not necessary to gain fat in order to gain muscle. All my clients gain muscle leading up to a bodybuilding show while losing body fat. All of them, men and women, doesn't matter. I always crack up at the big puffy bodybuilder who gains 50 pounds during the off season and then diets off 48 of it by show time. Why gain 50 pounds for a net gain of two? Why not gain five pounds and have all of it be muscle?
What you need to understand is that the body signals the building of muscle as part of its survival mechanism. It doesn't grow muscle because you want a killer double biceps pose. It grows muscle, and only grows muscle, in response to progressively greater gravitational stress. The greater the stress your body endures the greater the adaptation. This was actually proven 2700 years ago by the world's first bodybuilder, Milo of Croton, who roamed the hills of southern Italy with a bull over his shoulder.
Milo was perhaps the best wrestler in world at the time, having won ancient Greece's triple crown of wrestling a staggering seven times and the Olympic games five times. The secret to his incredible strength was the bull. Not the kind of bull you get from the broscientists online these days, but an actual cow. Milo picked up the critter shortly after it was born, slung it over his shoulders and walked the hills behind his farm until he couldn't carry it any longer. He did this every day. As the calf grew, so too did Milo. And so was born the progressive resistance principle.
What Milo proved is that in order to grow muscle the body must be subjected, repeatedly, to an ever increasing work load it cannot accomplish with the stock muscle allotment. In order to survive that stress, it builds muscle to become stronger and adapt.
And, that is IT. Other than some kind of rouge genetic factor, there is absolutely no other reason whatsoever your body will build muscle. In fact, the body will strive to get rid of muscle it's not using. If you doubt me, stick your arm in a cast for six weeks and see what you haver left after you cut it off. It will only build muscle if it needs it. And, if the stress is grave enough, it will build that muscle no matter what, even if calories are restricted.
You have to remember that a pound of fat has 3500 calories. If you weigh 200 pounds and you're at a fairly moderate 10% body fat, that means you have 20 pounds of fat on your body, that equates to 70,000 calories worth of potential energy on board, in addition to what you eat. So, unless you have zero body fat, your diet can consist of very few calories and you'll still have plenty of energy calories on board to keep you going. It might not feel very good, but you're not going to starve. And, if you're taking in the right nutrients, you're not going to lose muscle, in fact, with proper nutrients and stimulation in the gym, you'll grow muscle, even if calories are restricted.
As far as proper nutrients go, protein is going to be king. Building muscle requires protein, particularly the essential proteins, also known as essential amino acids, particularly the branch chain amino acids. These nutrients are termed “essential” because the body does not produce them, or does not produce them in adequate amounts, requiring you get them either from your diet, or high quality nutritional supplements.
Building muscle requires building blocks. The more you have on board the better your chances of building muscle. But, you also need to keep the machine well oiled. So, in addition to the amino acid element, you will also benefit from complete protein powders, vitamins and minerals and joint care supplements.
Growing muscle without getting fat is as possible as it is tedious. You have to work at it – hard. But, with consistency and attention to detail, you'll build it without having to battle pounds and pounds of unnecessary body fat.