Table 1.

Characteristics of representative muscle types

CharacteristicType 1Type 2AType 2X
Performance effect
    Force production potentialLowModerate-highHigh
    Fatigue resistance (endurance potential)HighModerateLow
    Contractile speedLowFastHigh
Cellular characteristic (mechanism)
    Glycolytic enzyme activityLow-moderateModerate-highHigh
    ATPase activityLowModerateHigh
    Myoglobin concentrationHighModerate-highLow
    Mitochondrial enzyme activityHighHighestLow
    Capillary densityHighModerateLow