Metformin, the most prescribed glucose-lowering medication and taken by 93% of our T2D study participants, has been shown to attenuate the training-enhanced peripheral insulin sensitivity and mitochondrial adaptations, and alters VO2peak improvements in adults with prediabetes (Konopka et al., 2019; Walton et al., 2019). The gene discussed is INS; the disease is prediabetes syndrome.