A Look At Your Muscles

The 3 Muscle Fiber Types Found In The Human Muscles

Type 1               “Red, slow twitch, aerobic fibers – fatigue resistant.”  These muscle fibers are rich in capillaries and myoglobin (which enhance oxygen delivery).  Individuals with a greater number of Type 1 muscle fibers tend to excel in endurance activities lasting longer than 3 minutes.

Type 2A              “Pink – moderately fast twitch.”  These muscle fibers have traits of both Type 1 and Type 2B.  Individuals with greater amounts of these muscle fibers tend to excel in activities lasting between 30 seconds and 2 minutes and have a moderate level of strength and aerobic capacity capabilities.

Type 3B              “White, fast twitch, anerobic.”  These muscle fibers are large in diameter and well suited for brief, powerful contractions.  Individuals with greater amounts of these muscle fibers tend to excel at high explosive activities such as maximal lifts and sprinting or jumping.  These are also fibers which have the greatest potential for hypertrophy (muscle growth and size).

Which muscle fiber type do you think you have more of?