NY Times: Work Out Now, Ache Later: How Your Muscles Pay You Back. The old culprit was lactic acid. Now scientists aren’t sure. They’re focusing on the theory that the pain is caused by microscopic tears in the muscles.
NY Times: Work Out Now, Ache Later: How Your Muscles Pay You Back. The old culprit was lactic acid. Now scientists aren’t sure. They’re focusing on the theory that the pain is caused by microscopic tears in the muscles.