Prescribing high-intensity interval exercise by RPE in individuals with type 2 diabetes: metabolic and hemodynamic responses

We tested the hypothesis that rating of perceived exertion (RPE) is a tool as efficient as the heart rate (HR) response to the cardiopulmonary exercise test (CPX) for prescribing and self-regulating high-intensity interval exercise (HIIE), and that metabolic and hemodynamic response to HIIE is superior than to continuous moderate-intensity exercise (MICE) in individuals with type 2 diabetes mellitus (T2DM). Eleven participants (age = 52.3 +/- 3 years) underwent HIIE prescribed and self-regulated by RPE (HIIERPE; 25 min), HIIE prescribed and regulated by an individual's HR response to CPX (HIIEHR; 25 min), MICE prescribed and self-regulated by RPE (30 min) and control (30 min of seated resting) intervention in random order. HR, blood pressure (BP), capillary glucose, endothelial reactivity, and carotid-femoral pulse wave velocity were assessed before, immediately after, and 45 min after each intervention. Exercise HR, speed, and distance were measured during exercise sessions. Twenty-four-hour ambulatory BP was measured after each intervention. Exercise HR, speed, and distance were similar between HIIERPE and HIIEHR. BP response was not different among HIIERPE, HIIEHR, and MICE. Capillary glycaemia reduction was greater (P < 0.05) after HIIERPE (48.6 +/- 9.6 mg/dL) and HIIEHR (47.2 +/- 9.5 mg/dL) than MICE (29.5 +/- 11.5 mg/dL). Reduction (P < 0.05) in 24-h (6.7 +/- 2.2 mm Hg) and tendency toward reduction (P = 0.06) in daytime systolic (7.0 +/- 2.5 mm Hg) ambulatory BP were found only after HIIERPE. These results suggest that HIIE is superior to MICE for reducing glycaemia and ambulatory BP, and that the 6-20 RPE scale is a useful tool for prescribing and self-regulating HIIE in individuals with T2DM.