INS and Obesity: The strengths of this study include 1) the inclusion of a lean, healthy group to rule out attenuated responses due to obesity or type 2 diabetes, 2) the application of a HIIT-protocol recruiting several lower and upper body muscle groups to maximize the insulin-sensitizing effect, 3) the supervised, group-based training sessions and the non-weight-bearing approach to ensure adherence and lack of injuries, and 4) conduction of the majority of the training sessions in the afternoon, which may enhance the metabolic benefits (32, 41).