Slow twitch fibers

Slow twitch fibers Slow-twitch fibers are muscle fibers that are used more when compared to the rest. Your legs are full of slow-twitch fiber because you are on your feet much of the time.

Fast-Twitch versus Slow Twitch Fibers Slow-twitch fibers (Type I) More resistant to fatigue Associated primarily with long-duration, aerobic-type activities ...

However, some people inherit a high percentage of slow twitch fibers that enhance their performance in endurance activities, such as long distance runners. Most world class marathon runners have a very high amount of slow twitch fibers.

In general, slow twitch fibers are activated first followed by larger fast twitch fibers. Now when muscles begin to fatigue the asynchronous firing of fibers become more and more synchronized (Butchal, 1950). This allows for greater force production.

In general, many of us will have about 50% slow twitch fibers and 50% fast twitch fibers, although it will differ between individuals.

Slow twitch fibers have smaller nerves, thereby twitch much slower, however they have a higher number of mitochondria, which increases their oxidative capacity.

See also: Fiber, Muscle fiber, Slow, Aerobic, Endurance