Relationship between physical exercise, muscle damage and delayed-onset muscle soreness

Abstract

The objective of the present study was to investigate the relationship between physical exercise involving muscle damage and delayed-onset muscle soreness (DOMS). A literature review of national and international periodicals was carried out. Muscle structures (membranes, Z-line, sarcomeres, T tubules and myofi brils) can become damaged as a result of an imposed mechanical overload. Of greatest note are exercises requiring strength, particularly when muscular action is eccentric. Damage to skeletal musculature can be analyzed by direct methods (muscle biopsy or magnetic resonance) or by indirect methods (maximum voluntary movement, subjective pain perception scales, analysis of enzyme and protein concentrations in blood). Creatine kinase (CK), lactate dehydrogenase (LDH), myosin heavy chain fragments, troponin-I and myoglobin can be used as indirect markers of muscle damage. Both DOMS and muscle damage can be infl uenced by the type of activity, with emphasis on eccentric muscle movements, type of exercise, velocity of the movement, interval period between series, the level of individual fi tness, this last primarily affecting beginners. When myotrauma occurs, muscle damage repair is initiated by leukocytes migrating to the injured area, although, the histamines, prostaglandins, kinins and K+ produced by neutrophils and macrophages stimulate free nerve endings in the muscle, causing the DOMS. Despite this apparent relationship between muscle damage and DOMS, it is not possible to establish a linear relationship between these two variables, since published data are divergent.