Accumulation of lactic acid in muscles

Options

A. Lowers `P^H`
B. Increase pH
C. Is good for health
D. Removes fatigue

Answer

### Step-by-Step Solution:

1. **Understanding Lactic Acid Accumulation**: When muscles perform intense exercise, they may not receive enough oxygen to produce energy through aerobic respiration. As a result, they switch to anaerobic respiration, which leads to the production of lactic acid.

2. **Effect on pH Levels**: The accumulation of lactic acid in the muscles causes a decrease in the pH level, making the environment more acidic. This change in pH is significant because it affects muscle function.

3. **Muscle Fatigue**: The lower pH level resulting from lactic acid accumulation leads to muscle fatigue. This is because the acidic environment interferes with the muscle's ability to contract effectively.

4. **Development of Muscle Cramps**: As fatigue sets in, individuals may also experience muscle cramps. This is a result of the muscles being unable to relax properly due to the acidic conditions.

5. **Conclusion**: Therefore, the accumulation of lactic acid in muscles primarily leads to a decrease in pH, resulting in fatigue and muscle cramps.

### Final Answer:
The accumulation of lactic acid in muscles lowers the pH level, leading to muscle fatigue and cramps.

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