This archive report was first published on 1 October 2019.
Understanding Fast-Twitch and Slow-Twitch Muscles ¶
When it comes to fitness, the terms fast-twitch and slow-twitch muscles are often associated with spasms, but they play a crucial role in exercise and movement. Published on October 1, 2019, by WomensHealthMag.com, a trainer explains the difference between these two types of muscle fibers.
Slow-twitch muscles, also known as Type I muscle fibers, are the first line of recruitment when a muscle contracts. They are able to create their own energy using oxygen, making it possible to sustain a lower level of force for an extended period of time. According to the American Council on Exercise (ACE), slow-twitch muscles are used for low-intensity exercise like swimming, power walking, running, and biking.
On the other hand, fast-twitch muscles, or Type II muscle fibers, are engaged when slow-twitch muscles can’t generate the amount of force needed for the activity. They are larger and denser than slow-twitch muscles, making them more powerful. Fast-twitch muscles are used for hardcore exercises like high-intensity interval training.
Hybrid muscle fibers, which are a mix of Type I and Type II muscle fibers, are used when transitioning between low-intensity and high-intensity exercises. These fibers are found in greater amounts amongst cross-trained athletes who consistently train in both aerobic and anaerobic exercises.
Training Your Fast-Twitch Muscle Fibers ¶
The good news is that muscle fibers can be super responsive to training. However, fast-twitch muscles can convert to hybrid or slow-twitch over time if they’re not trained properly. To stay on top of this, it’s essential to incorporate high-force output movements into your workouts.
According to Albert Matheny, MS, CSCS, co-founder of SoHo Strength Lab in New York City, you can do this by incorporating short resistance exercises that require lots of power into your workouts. Examples include plyometric box jumps, hard-and-fast sprints, and one-rep max lifts on a variety of exercises.
It’s also essential to allow for proper recovery time between sessions. As George Bristow, MS, a certified strength and conditioning coach at Platform Strength in Denver, explains, explosive training has the highest load on your central nervous system, which requires a longer recovery time. It’s recommended to allow 72 hours in between sessions for each muscle group involved.
