If you wanted to reduce your risk of injury, you could move your joints through their full range of motion on a regular basis. This would improve which component of physical fitness?

• A. Cardiorespiratory endurance
• B. Body composition
• C. Muscle endurance
• D. Flexibility

Answer: (D)

Moving joints through their full range of motion regularly improves flexibility, which is the ability to move joints through their full movement arc with ease. When you regularly stretch and move through your complete ROM, muscles, tendons, and other soft tissues stay supple and joints stay mobile. This helps you move more freely and maintain good technique during activities, reducing the chance of overstretching a muscle or putting a joint in an awkward position that could lead to injury.

Other fitness components focus on different things: cardiorespiratory endurance is about how efficiently the heart and lungs supply oxygen during sustained activity, body composition reflects the amount of fat versus lean tissue in the body, and muscle endurance is about how long muscles can sustain a contraction or repeated effort. Those areas aren’t primarily about how far your joints can move, which is why flexibility is the best-fit choice here.