The mechanisms by which physical activity prevents the occurrence of MS include the following: (i) increase in the number of mitochondria in muscle fibers through the production of peroxisome proliferators, improving the oxidative capacity of the muscles and reducing systemic inflammation; (ii) secretion of metabolically beneficial hormones, especially irisin; (iii) reversal of insulin resistance by the muscles promoting the use of serum glucose as a substrate; (iv) reduction in hepatic lipogenesis due to increased use of fatty acids by the muscles.40 The gene discussed is INS; the disease is myeloid sarcoma.