subject: Secrets To Building Muscle Fast [print this page] Muscles are made of three kinds of fibersMuscles are made of three kinds of fibers. There are slow-twitch, or Type I, fibers, and there are two fast-twitch fibers called Type IIa and Type IIb fast-twitch fibers.
Slow-twitch fibers are those that are used mainly for endurance types of sports and exercise like distance running. You've never seen a distance runner that looks really muscular, have you? You won't. It's not that they aren't strong, they are. It's just that the muscles that they have developed are those used for endurance rather than strength.
Type IIa fast-twitch fibers are capable of more force than slow-twitch fibers, but they tire more quickly. Type IIb fast-twitch fibers are capable of even greater force than Type IIa fibers, but they tire even more quickly. The fast-twitch fibers are basically for exerting force, and the slow-twitch fibers are for exerting force over a period of time.
While all muscle fiber is important and needs to be developed to some degree if you want to build visible muscle mass, you need to concentrate your efforts on building fast-twitch fibers both Type IIa and Type IIb.
The speed and ease at which you will develop fast-twitch fiber muscle is determined a great deal by your genetic makeup. Your ratio of slow-twitch fiber to fast-twitch fiber is pretty much determined at birth, so there's nothing you can do about that. But even if you have a higher percentage of slow-twitch fiber, that doesn't mean that you can't develop muscles. It just means that you are going to have to work harder at it and that it's going to take longer.
Muscle develops when stress is put on a muscle and small tears occur. When the body repairs the damage, it actually builds more muscle to repair the damage, and muscles get bigger.
