IRS1 and polycystic ovary syndrome: It has been shown that the mRNA levels of both insulin receptor substrate-1 (IRS-1) and glucose transporter-1 (GLUT-1) were increased in overweight/obese women with polycystic ovary syndrome following a lifestyle intervention that included increased physical activity (prescribed aerobic activity for 45 min two or three times/week) [151], suggesting that the changes occurring at a molecular level after exercise directly affect the mechanisms involved in insulin sensitivity and glucose metabolism in muscle.