Distinguishing Features Of Different Muscle Fiber Types
Type A Fast-twitch Muscle Fibers
Fast-twitch muscle fibers are responsible for helping out during the heavy work done by the body. This is the reason that they also get tired before time. They are designed with large motor neurons and very low mitochondrial density. Utilization of oxygen is also not very efficient in there muscle fibers, that is why they do not persist for long. Oxygen lends support to the muscle during the contractions. Energy production in these muscle fibers depends on creatine phosphate and glucose. They can contract frequently for only about twenty seconds, so they do not get the time to use or take benefits from the stored body fat.
Type B Fast-twitch Muscle Fibers
Activities that are of short duration are performed by the body with the help of Type B fast-twitch muscle fibers. Those of you who are sprinters mostly take advantages from these muscle fibers in order to attain extreme speed for a short period of time. Large motor neurons exists in these muscle fibers similar to the Type A fibers. They have a very high mitochondrial density and resist to fatigue in an intermediate rate. These muscle fibers are way more efficient in consuming oxygen as compared to Type A muscle fibers and contract frequently for a longer period of time.
Slow-twitch Muscle Fibers
Activities of extended duration or of medium-to-mow intensity are performed by the body with the help of Slow-twitch muscle fibers. These muscle fibers do not fatigue out and are very efficient in utilizing oxygen. Characteristically, they do not generate a significant amount of force because their contractions are slow as compared to the other types of muscle fibers. They are designed with a very high mitochondrial density. For the efficient utilization of oxygen by these muscle fibers, the credit goes to a large number of capillaries.
Training the Different Muscle Fiber Types
A slight variation in training is common for each of the different types of muscle fiber.
Putting on less strength while performing Type B muscle training is required as compared to Type A, and the duration of time for Type B is also longer.
Unlike the Type A, Type B muscle fibers require lesser force in exercise, but each session has to last longer. A suitable example for this is 30-40 intervals with 10 repetitions for a minute, being done at a moderate speed. For instance in weight training, 6-10 times repeated routine is recommended as it uses the muscles ability to oxidize more. The muscles are designed to endure pressure, thus extensive exercise regimes are required for developing them. Run farther, cycle more; swim an extra leap or two.
It is important to understand and readjust the workout routines, as per the requirement of every muscle fiber in the body that needs to be built up.