Which fitness component is the ability of the heart and lungs to supply oxygen to working muscles?

• A. Muscular Strength
• B. Cardiovascular Fitness
• C. Flexibility
• D. Speed

Answer: (B)

The ability of the heart and lungs to supply oxygen to working muscles is cardiovascular fitness. This component reflects how efficiently your heart can pump blood and how well your lungs can oxygenate that blood, delivering oxygen to muscles during sustained activity. With better cardiovascular fitness, you can sustain aerobic efforts longer, recover more quickly, and perform at higher intensities because your body becomes more efficient at moving and using oxygen. Training this involves continuous, rhythmic activities that use large muscle groups—like running, cycling, swimming—progressively increasing in effort to push your heart and lungs to adapt.

Muscular strength is about how much force a muscle can produce in a single effort, not how efficiently oxygen is delivered. Flexibility concerns the range of motion around joints, and speed relates to how fast you can move, which are influenced by different factors and don’t specifically describe oxygen delivery to muscles.