Soreness is a phenomenon that just most people have experienced. Waking up the morning after an exercise session with tender and inflamed muscles, unable to summon the capacity to engage in regular activities, is especially common among those who are not used to strenuous exercise. While soreness is a completely normal physiological response, it is not a pleasant one, and its arc usually lasts for several days.
Post-exertion soreness is a symptom of a much larger condition known as delayed onset muscle soreness. It occurs when you engage in an intensity of exercise to which you are generally not accustomed. This type of high-intensity and high-tension exercise causes structural damage in your muscles' fibers, and during the subsequent recovery period that follows, soreness is just one of many various symptoms. Stiffness, swelling and a loss of strength will also develop.
Soreness will take at least eight hours to appear but is usually delayed until the following morning. According to a 1993 study published in The Journal of Physiology by researchers from Ohio University, soreness peaks two days later, begins to abate by the third day and finally disappears completely by the end of the seventh day. This mirrors closely the complete arc of recovery, since the muscle is nearly mended within a week of the initial exercise.
The duration of the soreness and pace of the recovery are both dictated by the body's ability to clean up and repair the damage within the muscles. This process is usually quite consistent and predictable. In a review of available literature, a group of various scientists, publishing in the Journal of Strength and Conditioning Research, cited several studies that explored whether certain treatments, including muscle immobilization and non-steroidal anti-inflammatory drugs, may expedite the healing process, but the results of these studies were either contradictory or needed further testing and confirmation before any broad conclusions could be drawn concerning their efficacy.
Although it may take up to a week before the soreness fully diminishes, it is safe to engage in strength training or physical activity before then. Many people choose to wait two or three days; if you are worried that the soreness may negatively influence your routine, then you might consider working different muscle groups on different days. For example, if you worked your chest muscles on Monday, then you can work the triceps on Wednesday. This allows each muscle group sufficient time to heal before the next session.