Question

Which of the following is the long-term effect of exercise on the respiratory system?

• A. Residual volume increases
• B. Respiratory rate increases
• C. Stroke volume increases
• D. The rate of exchange of gas increases

Hint:

Be careful with system categories! Stroke Volume is an excellent long-term training effect, but it belongs exclusively to the cardiovascular system, not the respiratory system.

Answer 1

The Correct Option is D

Step 1: Differentiating Acute vs. Chronic Physiological Responses:

• Acute effects are immediate, temporary responses that occur during exercise (e.g., immediate increases in respiratory rate).
• Chronic/Long-term effects are permanent structural or functional adaptations resulting from consistent, long-term training.

Step 2: Analyzing the Options:

• Residual Volume (A): Typically decreases or remains steady with aerobic training as vital capacity improves.
• Respiratory Rate (B): Increases sharply during acute exercise, but decreases at rest over the long term due to improved efficiency.
• Stroke Volume (C): Is an adaptation of the cardiovascular system, not the respiratory system.
• Rate of Gas Exchange (D): Long-term aerobic training increases alveolar surface area, capillary density, and hemoglobin binding efficiency, leading to a permanent increase in the rate of gas exchange ($O_2$ and $CO_2$).

Step 3: Conclusion:
Therefore, option (D) is the correct long-term respiratory adaptation.