How is "cardiorespiratory fitness" best defined?

Cardiorespiratory fitness is best defined as the ability of the heart and lungs to supply oxygen during sustained physical activity. This aspect of fitness is crucial for overall health and well-being, as it indicates how effectively the cardiovascular and respiratory systems work together to deliver oxygen to the body while simultaneously removing carbon dioxide. During activities such as running, cycling, or swimming, adequate cardiorespiratory fitness allows individuals to perform prolonged activities without excessive fatigue.

This definition encompasses both the efficiency of the heart (which pumps oxygen-rich blood) and the lungs (which oxygenate blood), highlighting the importance of endurance exercise in improving this fitness component. Enhancing cardiorespiratory fitness through regular aerobic exercise can lead to numerous health benefits, including improved heart health, better metabolic function, and enhanced mood and energy levels.

Other definitions related to muscle strength, muscle mass, or bone and joint strength do not address the specific functions of the heart and lungs and their role in sustaining physical activity.