Which fitness assessment measures the ability of muscles to do repeated contractions over time?

• A. Muscular flexibility
• B. Cardiovascular endurance
• C. Muscular strength
• D. Muscular endurance

Answer: (D)

Muscular endurance is about how long muscles can keep contracting repeatedly against resistance or how long they can sustain a contraction before fatigue. This is why assessments that count how many repetitions you can perform (or how long you can hold a contraction) best measure this capability. It differs from muscular strength, which looks at the maximum force a muscle can produce in a single effort, and from cardiovascular endurance, which relates to the body's ability to supply oxygen to working muscles over time. Flexibility, meanwhile, is about the range of motion around a joint. So a test that measures repetitions or sustained effort in a muscle group is assessing muscular endurance.