Delayed Onset Muscle Soreness (DOMS)
Delayed onset muscle soreness (DOMS) is a common condition experienced after exercise, particularly high-intensity and eccentric exercise. It typically presents as muscle pain and stiffness that develops 24 to 72 hours after exercise and can last for several days. At a biological and molecular level, DOMS is caused by a combination of muscle fiber damage, inflammation, and oxidative stress.
Muscle fiber damage: High-intensity and eccentric exercise can cause microscopic tears in the muscle fibers, leading to muscle soreness and inflammation. These tears disrupt the structural integrity of the muscle fibers, triggering an inflammatory response as the body works to repair the damaged tissue.
Inflammation: The inflammatory response to muscle fiber damage involves the activation of immune cells, such as macrophages, and the release of pro-inflammatory cytokines, such as interleukin-1 beta (IL-1β) and tumor necrosis factor-alpha (TNF-α). These cytokines are involved in recruiting immune cells to the site of injury, removing cellular debris, and initiating tissue repair.
Oxidative stress: Eccentric exercise, in particular, can also cause oxidative stress within the muscle fibers. This occurs when the body's antioxidant defenses are overwhelmed by the production of reactive oxygen species (ROS), which are highly reactive molecules that can damage cellular components, such as proteins, lipids, and DNA. The accumulation of ROS can lead to further muscle fiber damage and inflammation.
Together, muscle fiber damage, inflammation, and oxidative stress contribute to the development of DOMS. While DOMS is a normal and expected response to exercise, there are strategies that can help alleviate symptoms, such as foam rolling, stretching, massage, and non-steroidal anti-inflammatory drugs (NSAIDs). It's important to note, however, that excessive use of NSAIDs can impair muscle regeneration and delay recovery. Therefore, a balanced approach that allows for adequate recovery time and incorporates proper nutrition and hydration is recommended to prevent and manage DOMS.
