AbstractIrisin is a myokine involved in adipocyte transformation. Its main beneficial effects arise from increased energy expenditure. Irisin production is particularly stimulated by physical exercise. The present study investigates the changes of plasma irisin in type 2 diabetic patients performing 2 different training modalities. Fourteen type 2 diabetic patients underwent 4 week of supervised high-intensity interval training (HIT; n=8) or continuous moderate-intensity training (CMT; n=6), with equivalent total amounts of work required. Plasma samples were collected in the resting state atbaseline and one day after the exercise intervention to analyse resting plasma irisin, blood lipids, blood glucose, hsCRP, Adiponectin, Leptin and TNF-α concentrations. In addition, body composition and VO2peak were determined Resting plasma irisin increased after HIT (p=0.049) and correlated significantly with plasma fasting glucose at follow-up (r=0.763; p=0.006). CMT did not significantly change the amount of plasma irisin, although follow-up values of plasma irisin correlated negatively with fat-free mass (r=−0.827, p=0.002) and with fasting plasma glucose (r = − 0.934, p=0.006). Plasma irisin was found to increase with higher training intensity, confirming the assumption that exercise intensity, in addition to the type of exercise, may play an important role in the stimulation of the irisin response.