Delayed onset muscle soreness

Delayed onset muscle soreness or DOMS refers to muscle soreness which begins 1-2 days after exercise; it is not a symptom of illness. Peak soreness is at 2-3 hours after exercise and can vary between mild and severe.

Athletes will experience DOMS after high intensity exercise work-outs. At low intensity exercise/work-outs the athlete will rarely experience soreness.

Signs and symptoms

 * Muscle pain
 * Stiff muscles
 * Muscle pain is relieved when muscles are warmed up with gentle physical activity, pain returns as they cool down

Possible causes
Sore muscles after physical activity, known as delayed onset muscle soreness (DOMS), can occur when you start a new exercise programme, change your exercise routine, or increase the duration or intensity of your regular workout.

No lactic acid build-up
Many people believe that DOMS is the result of lactic acid production, but lactic acid is not involved. The cause of DOMS is microscopic injury to muscle fibres, which leads to stiffness and soreness.

The damage to muscle cells triggers an inflammatory response which involves neutrophils and macrophages. These cells removes the damaged muscle tissue and release enzymes. The muscle fibers are then repaired.

ME/CFS
Delayed onset muscle soreness is not regarded as a diagnostic symptom of ME/CFS, and should not be confused with muscle pain caused by ME/CFS, although this often does increase with post-exertional malaise. In ME/CFS, muscle pain occurs when no exercise or physical activity has taken place.

Prevention and treatment
In healthy people, exercise training and stretching generally prevent DOMS, but are ineffective for middle pain in ME/CFS. 

Pain relief medications are typically recommended for muscle pain in ME/CFS.

Notable articles

 * 2018, Advances in Delayed-Onset Muscle Soreness (DOMS): Part I: Pathogenesis and Diagnostics - (Abstract)
 * 2019, Advances in Delayed-Onset Muscle Soreness (DOMS) - Part II: Treatment and Prevention - (Abstract)

Learn more

 * Pain after exercise - NHS
 * Doms away! Is delayed onset muscle soreness inevitable after a workout? - The Guardian
 * Postexercise Muscle Soreness - Medscape