I wrote this review in view of the great importance of preventing and treating diabetes by exercise. For the interpretation of the results, it can be taken into account that HIIT can stimulate IGF1 secretion [Herbert P, Hayes LD, Sculthorpe N, Grace FM. High-intensity interval training (HIIT) increases insulin-like growth factor-I (IGF-I) in sedentary aging men but not masters' athletes: an observational study. Aging Male. 2017;20(1):54-59.]. Given the role that IGF1 plays in regulating blood sugar, resulting in insulin resistance change [Abbas A, Grant PJ, Kearney MT. Role of IGF-1 in glucose regulation and cardiovascular disease. Expert Rev Cardiovasc Ther. 2008;6(8):1135-1149.], and that REHIT has no acute effect on insulin sensitivity [Metcalfe R1, Fawkner S2, Vollaard N3. No Acute Effect of Reduced-exertion High-intensity Interval Training (REHIT) on Insulin Sensitivity. Int J Sports Med. 2016;37(5):354-358.] future research should determine the differences in which the two types of exercise induce blood glucose lowering in type II diabetes sufferers. For now, I assume that REHIT "forces" the pancreas to secrete more insulin to metabolize the oxygen debt.