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:

To distinguish between Cardiovascular and Respiratory effects: If it involves blood flow or the heart (like Stroke Volume), it's Cardiovascular. If it involves breathing or gas exchange, it's Respiratory.

Answer 1

The Correct Option is D

Step 1: Understanding the Concept:
Long-term effects (chronic adaptations) of exercise refer to the permanent physiological changes that occur in the body after regular training over weeks or months, as opposed to immediate (acute) responses.
Step 2: Detailed Explanation:

1. Rate of exchange of gas (D): Regular exercise increases the size and number of alveoli and the density of capillaries surrounding them. This improves the efficiency and rate of diffusion of $O_2$ and $CO_2$ between lungs and blood.
2. Respiratory rate (B): Actually decreases at rest as a long-term effect because the lungs become more efficient.
3. Stroke volume (C): This is an effect on the cardiovascular system, not the respiratory system.
4. Residual volume (A): This generally decreases or remains stable; an increase would imply less air being exhaled.
Step 3: Final Answer:
The long-term effect is an increase in the rate of exchange of gas.