During heavy exercise the breathing rate of a person slows down. (T/F)

Explanation

**Step-by-Step Solution:**

1. **Understanding the Question**: The statement claims that during heavy exercise, a person's breathing rate slows down. We need to determine if this is true or false.

2. **Analyzing Heavy Exercise**: During heavy exercise, the body requires more energy. This increased energy demand is primarily due to the muscles working harder.

3. **Oxygen Requirement**: To produce more energy, muscle cells need more oxygen. Therefore, the body must increase its oxygen intake to meet this demand.

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