Fitness Specialist Question:

When it comes to exercise, burning is often used to refer to the feeling of when muscles experience an accumulation of metabolic waste, which creates fatigue. Acidosis is a change in blood acidity—specifically, elevated levels of lactic acid and hydrogen ions—that is often the result of moderate- to high-intensity exercise. A burning sensation in a muscle is an indication of acidosis. It’s also a sign that it is time for a recovery period to allow the body to remove metabolic waste from the working muscles and replenish the nutrients required to continue performing muscle contractions.