Slow Twitch Muscle Exercises

People on Jacques Cartier Bridge in Montreal running marathon

There is a reason that sprinters tend to be larger and longer distance athletes, such as marathon runners, are smaller. It all comes down to muscle fibers. Your muscles are composed of slow-twitch and fast-twitch muscles; they determine how far and how fast you can go. Fast-twitch are bigger fibers compared to slow-twitch fibers. Unfortunately, you can’t switch a fast twitch muscle fiber into a slow twitch one, but you can train each type to become as efficient as possible.

Slow-Twitch Basics

The composition of slow-twitch to fast-twitch muscles in your body is largely based on genetics. There are three different types of muscle fibers: slow twitch, fast twitch A and fast twitch B. Your slow twitch muscles, also called type I, are used during aerobic activity. These muscles are built for endurance. They are slow to contract but they are very resistant to fatigue. The fast twitch muscle fibers contract faster but they fatigue much sooner. These muscle fibers are recruited for sprinting or jumping.

Weight Lifting Training

Slow-twitch muscle fibers are all about endurance while fast-twitch muscles fibers focus on muscular strength. This difference plays a major role in how you should do your lifting routine. Slow-twitch strength training is executed with a higher number of repetitions than fast-twitch training. Yet, you will lift a lighter weight with slow-twitch exercises.

Cardio Training

When doing cardio to train slow-twitch muscle fibers, you want to choose slower, endurance activities. An example of this is a long, slow run. This focuses on your slow-twitch muscles and improves their endurance capacity. Over time, this builds stronger slow-twitch fibers so you’ll use less energy to maintain a given speed. Another way to train slow-twitch fibers is with long intervals. These are cardio intervals performed at an increased pace for two to five minutes. This forces your slow-twitch fibers to work at their top contraction speed and it makes your body more efficient at switching between slow twitch and fast twitch.

Getting Faster and Stronger

Even if your body composition is mainly slow-twitch muscle fibers, that doesn’t mean you can’t get faster and stronger. If this is the case, you need to increase the intensity of your strength training workouts and step up the speed of your cardio training. A study published in the “Scandinavian Journal of Medicine and Science in Sports” in 2010 showed that doing strength training directly followed by endurance exercise increased overall cardio endurance, strength and force in endurance athletes.