The Easiest and Fastest Way to Determine an Athlete's Muscle Fiber Type

Muscle fiber type can be an important factor for individualization of an athlete's training program.

There are two basic muscle fiber types: type I and type II.

The type I fibers are called slow-twitch because they produce low amounts of strength and power and are subsequently best suited for endurance activities.

The type II fibers are called fast-twitch because they produce high amounts of strength and power and are thus better suited for speed and explosive events.

The best way to determine the general fiber make-up of a trainee is to do a vertical jump test.

The height of the jump is important but only second to the way the jump is performed. 

At the start of the vertical jump, a slow-twitch athlete will tend to dip very low and slowly into a squat position before transitioning concentrically to a vertical displacement. 

On the other hand, a fast-twitch athlete will have a short and forceful dip to create higher acceleration for the jump.

The advantage of this test, besides the fact that it's highly practical, is that the test doesn't lie as the athlete's jumping mechanics is subconscious and will usually provide an unbiased response.

The only 100% accurate reading of a muscle fiber type is through a muscle biopsy, but if you're looking for a practical test that can be done in less than a minute, I highly suggest you use the vertical jump test. 

Stephane CazeaultComment