Muscle pain after vigorous exercise is normal, even for well-conditioned athletes. Most people know that stretching before exercise is important, but in addition, stretching after exercise can be equally important to relieve muscle pain. The theory behind muscle pain after exercise is that it involves buildup of lactic acid in the tissues. If you ask a sports medicine doctor, they will tell you that the most important thing to do for treatment of muscle pain related to exercise is to use heat therapy before exercise and cold therapy afterwards. It is also perfectly acceptable to use over-the-counter pain medicines such as acetaminophen or ibuprofen at times when you overdo it.