Which kind of people have a higher vital capacity? What is the value in a normal adult?

Explanation

### Step-by-Step Solution:

1. **Understanding Vital Capacity**:
- Vital capacity is defined as the maximum amount of air a person can expel from the lungs after a maximum inhalation. It is a crucial measure of lung function.

2. **Components of Vital Capacity**:
- Vital capacity is the sum of three different volumes:
- **Inspiratory Reserve Volume (IRV)**: The amount of air that can be inhaled after a normal inhalation, approximately 1300 ml.
...