The ability of a muscle group to perform repeated contractions over a period of time sufficient to cause muscular fatigue or to maintain a specific percentage of maximum voluntary contraction for a prolonged period of time is called what?

Muscle endurance

Explanation:

Muscular endurance is the ability of a muscle or collections of muscles to satiate or endure repeated contractions against a resistance for an extended period of time. It is one of the components of muscular contractions, muscular fitness, along with muscular strength and power.

During exercise or training fitness, muscular endurance implies to the number of repetitions of a single exercise you can underg without needing to stop and rest.