INS and polycystic ovary syndrome: The primary findings of this secondary analysis of a 12-week intensified exercise intervention in overweight and obese women with and without PCOS was a substantial variation in insulin sensitivity, body fat and aerobic capacity changes in response to exercise, and although all participants improved VO2 peak (indicating improved fitness), approximately one–quarter did not improve insulin sensitivity and two-thirds did not reduce body fat by ≥5%.