Have sore muscles is a condition that can be caused by physical activity, such as exercise or sports, or by an injury. The term for this condition is 'ACHE, ' which is a four-letter word. Aches can range from mild to severe and can last for days or weeks. Symptoms of sore muscles include pain, stiffness, and tenderness in the affected area. Treatment for sore muscles includes rest, ice, compression, and elevation.