Thank you for the opportunity to help you with your question!
The difference between Type I, Type IIA, and Type II B are that:
Type I - referred to as “slow twitch oxidative”. Type I function are mainly for low force, power, and speed production. It is primarily used for high endurance.
Type IIA – referred to as “fast twitch oxidative.” Type IIA is characterized by medium force, power,a nd speed production. It is mainly for medium endurance.
Type IIB – referred to as “ fast twitch glycolytic.” Type IIB is characterized by high force, power, and speed production. It is mainly for low endurance.
The main difference between a slow twitch and fast twitch muscle units the fast twitch motor unit controls more muscle fibers and are larger. The fast twitch fiber is bigger and can produce more force.
Type II muscle units are capable of greater force than type I, but also fatigue more quicker.
Type I muscle fibers have the highest oxidative (aerobic) capacity and the lowest glycolytic (anaerobic) capacity. They have the smallest cross-sectional area. They contract slowly and able to hold a steady paced twitch for a long duration. They are primarily used for endurance by long distance runners, swimmers, and cyclists. Type I are conducive to aerobic activities because of their small cross-sectional area that can take up oxygen.
Type II muscle fibers have fast contractile speed. They have largest cross-sectional area and low oxidative capacity. They have the highest glycolytic (anaerobic) capacity. They are primarily for short fast burst of power. Some of the activities for Type II are sprinting, powerlifting, and bodybuilding.
Please let me know if you need any clarification. I'm always happy to answer your questions.
Content will be erased after question is completed.