Exercise-induced muscle damage (second phase)
Certain gene variations, or polymorphisms have been associated with exercise-induced muscle damage (i.e. individuals with certain genotypes experience greater muscle damage, and require longer recovery, following strenuous exercise). Knowing how someone is likely to respond to a particular type of exercise could help coaches/practitioners individualise the exercise training of their athletes/patients, thus maximising recovery and adaptation, while reducing overload-associated injury risk.
PHASES OF MUSCLE DAMAGE
The exercise can produce muscle damage through a series of alterations of two types, some of early onset and mechanical origin while others are consequences of the previous ones and consist on the inflammatory process.
The second phase of exercise-induced muscle damage consists of an inflammatory response. The degenerative products of the muscle fiber, especially the tissue polysaccharides, through the process called chemotaxis, produce that the leukocytes approach the cell to start the inflammatory process. With muscle damage induced by exercise, there is also an increase in cytokines, mainly IL1B, IL6 and TNFα, activated by the increase in free radicals and prostaglandins, which increase the inflammatory process. Polymorphisms or variants in the genes that code for these cytokines seem to be involved in the development of this second inflammatory phase of muscle damage.
GENE OR REGION STUDIED