Is it safe to be working out while sore? The answer to this question depends on the severity of muscle soreness, which can range from slight tenderness to debilitating pain. Delayed onset muscle soreness (DOMS) happens 1-2 days after exercise. The most likely cause of DOMS is microscopic muscle tears or a breakdown in muscle tissue that occurs during a workout. Introducing new activities or suddenly increasing the intensity can cause DOMS to occur. During periods of severe muscle soreness, a person has impaired coordination, less shock absorption, and a shortened range of motion. If you exercise while very sore you are likely to alter your body mechanics putting more stress on ligaments and tendons and therefore increasing your risk of injury. Should You Work out When You are Sore? Overreaching is the state of training intensely without rest. This leads to overtraining and a decline in athletic performance. It takes several weeks to months for this condition to occur, but watch fo...