Figure 3.

Representation of the telomere-shelterin association and effect of exercise. The ends of the chromosomes are protected by the shelterin protein complex, which prevents them from being recognized as damaged sites and from being erroneously repaired and recognized as double-strand breaks, and can generate chromosome instability. Exercise assist in maintaining or improving physical activity and is one of the main interventions for sarcopenia. Its effect lies in preventing the decrease in satellite cells, the increase in fatty tissue infiltrates in muscle fibers, and assists in obtaining bone mass, muscle mass, and skeletal muscle strength. Although exercise generates an increase in the formation of free radicals, it maintains the balance between the number of pro-oxidants and antioxidants. It also helps maintain and increase the length of telomeres, thus preventing erosion of the ends of chromosomes. Key components of the sheltering: TRF1 (telomeric repeat-binding factor 1); TRF2 (telomeric repeat-binding factor 2); POT1 (protection of telomeres protein); PIP1 (POT1-interacting protein 1); TIN2 (TRF1-interacting nuclear factor 2); and RAP1 (repressor activator protein 1).