Knowing the difference between fast twitch and slow twitch muscle fibers can play a huge role in your fitness routine!

Type II muscle fibers(fast twitch) workouts consist of Strength training, sprinting, plyometrics.. ..Type 11 fibers are for Short and intense exercises, with little endurance because the muscle fibers contract with a great amount of force but tire quickly..

While type 1 fibers(slow twitch) are for long distance, low intensity, with high endurance needed. Marathon runners for example have way more type 1 fibers than a power lifters do. Many sports require both of these fibers though, for example both soccer and basketball require both the recruitment of fast and slow twitch fibers due to the length of the sport and quick burst that are required to play these sports.

It is important to train both of these muscle fiber types for overall health no matter ones fitness goal. This basically means training both anaerobically(strength training/interval training and aerobically (long runs, walks, or hikes/also high rep calisthenic work) A combination of these types of exercises has been shown over and over again in research to be the ideal way for fitness health.

These muscle fibers are another reason way variation in ones workouts is crucial. Changing the amount of sets and reps not only confuses muscle it also ensures both fast and slow twitch muscle fibers are recruited in the same workout. You can adapt most exercises to either a fast- or slow-twitch training program by changing the amount of weight you lift and the number of repetitions performed.

Rest also plays an important part in fiber recruitment. Because of the chemical and physiological makeup of the different muscle fiber types, the amount of rest you need between sets will vary depending on what type of fibers your exercise is training.. Fast twitch are a slow recovery fiber and slow twitch have a much faster recovery time. This basically means take longer breaks(1-2 mins) between heavy strength/power moves as well as plyometric moves. For smaller muscle group training (with medium weight), resistance band training, and core training, less rest is needed(15-30 seconds).


Jason Whalen BA Exercise Science


Source: NCSA