Acute effects of high intensity training on cardiac function - A pilot study comparing subjects with type 2 diabetes to healthy controls.

Purpose. The purpose of this study was to evaluate the acute stress on the heart following one session of high intensity interval training in patients with type 2 diabetes (T2D) versus healthy controls. Methods. High intensity aerobic exercise was performed by 4x4 minutes intervals (90-95% of maximal heart rate), followed by a ramp protocol to peak oxygen uptake (VO 2peak ). Echocardiography was performed before, and 30 minutes after exercise. Heart rhythm was monitored 24h pre-exercise, during and 24h post exercise by Holter electrocardiogram. Results. After exercise we report a reduction in in both groups in the early diastolic peak mitral annular velocity, the ratio of mitral peak early to late diastolic inflow. Further, left atrial end-systolic volume was reduced after exercise. The LV end-diastolic wall thickness increased in CG. T2D had significant more supraventricular extrasystoles per hour before and after exercise. Conclusion. One single session of exhaustive exercise induced acute cardiac alterations in both left- and right-sided cardiac chambers with reduction in volumes and indices of systolic and diastolic dysfunction in both T2D patients and controls. There was no indication of different stress response in T2D compared to controls. ClinicalTrials.gov Identifier: NCT02998008