Question: If lactic acid is a toxin, how does it make our muscles stronger?

Laura Wales answered on 25 Jun 2015:

In short, lactic acid is produced when we exercise heavily. When we exercise heavily our muscles get stronger. Lactic acid isn’t all bad though.

During intense exercise, cells use anaerobic respiration to generate ATP to keep the muscles functioning. Although energy is still produced, it is in smaller amounts for each molecule of glucose. Glucose is not fully oxidised to carbon dioxide and water, and forms lactic acid instead.

If lactic acid accumulates faster than the body can get rid of it, it can result in lactic acidosis, which can affect the chemical balance in the body and can lead to vomiting, stomach pain and other symptoms. Rest, water along with deep and steady breathing can balance things again.