ABSTRACT
Background: Despite the evidence supporting metabolic benefits of high intensity interval exercise (HIIT), there is little information about the cardiovascular response to this type of exercise in patients with type 2 diabetes (T2D) and hypertension (HTA). Aim: To analyze the changes in heart rate at rest, at the onset and at the end of each interval of training, after twelve weeks of a HIIT program in T2D and HTA patients. Material and Methods: Twenty-three participants with T2D and HTA (20 women) participated in a controlled HIIT program. Fourteen participants attended 90% of more session of exercise and were considered as adherent. Adherent and non-adherent participants had similar body mass index (BMI), and blood pressure. A 1x2x10 (work: rest-time: intervals) HIIT exercise protocol was used both as a test and as training method during twelve weeks. The initial and finishing heart rate (HR) of each of the ten intervals before and after the intervention were measured. Results: After twelve weeks of HIIT intervention, adherent participants had a significant reduction in the heart rate at the onset of exercise, and during intervals 4, 5, 8 and 10. A reduction in the final heart rate was observed during intervals 8 and 10. In the same participants the greatest magnitude of reduction, at the onset or end of exercise was approximately 10 beats/min. No significant changes in BMI, resting heart rate and blood pressure were observed. Conclusions: A HIIT program reduces the cardiovascular effort to a given work-load and improves cardiovascular recovery after exercise.