How does increased fitness impact respiratory efficiency?

• A. Decreases lung capacity
• B. Improves respiratory muscle strength
• C. Reduces overall oxygen demand
• D. Increases risk of respiratory illness

Answer: (B)

Increased fitness leads to improved respiratory muscle strength, which enhances the efficiency of the respiratory system. As individuals become more physically fit, their respiratory muscles, particularly the diaphragm and intercostal muscles, adapt by becoming stronger and more efficient. This allows for greater lung expansion and contraction during breathing, facilitating a more effective exchange of gases - oxygen intake and carbon dioxide removal - during physical activity.

Stronger respiratory muscles contribute to greater tidal volume, meaning that more air is effectively moved in and out of the lungs with each breath. This is essential for meeting the increased oxygen demands of working muscles during exercise and supports overall endurance and performance.

Other options do not accurately represent the relationship between fitness and respiratory efficiency. Increased fitness does not decrease lung capacity, and while fitness can influence oxygen demand, it doesn't inherently reduce that demand; rather, it prepares the body to meet it more efficiently. Additionally, higher fitness levels often correlate with improved health outcomes, including a lower risk of respiratory illnesses, rather than an increased risk.