Question

With NMES, which muscle fibers are recruited first?

a. type I (slow twitch)
b. type II (fast twitch)
c. type III
d. type IV

Answer 1

With NMES, the first recruited muscle fibers are the type II (fast-twitch) fibers. These fibers are suited for short bursts of strength or speed and fatigue faster than slow-twitch fibers.

Step-by-step explanation:

When using Neuromuscular Electrical Stimulation (NMES), the muscle fibers that are recruited first are the type II (fast-twitch) muscle fibers. Slow-twitch (type I) muscle fibers are more efficient at using oxygen to generate more ATP for continuous, extended muscle contractions over a long time, such as in endurance sports. Fast-twitch fibers, on the other hand, are better at generating short bursts of strength or speed than slow-twitch fibers. They fatigue faster but are used in powerful bursts of movements like sprinting. Specifically, there are three types of skeletal fibers: Slow Oxidative (SO), Fast Oxidative (FO), and Fast Glycolytic (FG). FG fibers are the ones that have fast contractions and primarily use anaerobic glycolysis.