The Effect of Short-Term High-Intensity Interval Training on the Cardiovascular System

Abstract

Introduction. High intensity interval training (HIIT) is emerging as a time efficient strategy for health promotion. HIIT involves a short bout of exercise at a high intensity, interspersed by recovery periods in preparation for the next bout. HIIT has resulted in improved health markers in adults with cardiometabolic disease (Monique et al., 2015). There is growing evidence from healthy populations that HIIT leads to a range of cardiovascular and metabolic benefits that are similar to or greater in magnitude than those achieved with regular continuous aerobic exercise (Keating et al., 2014; Noybo et al., 2010). The aim of the study was to determine the effect of high-intensity interval training on the CVS in individuals who were actively exercising for health enhancement. Methods. The subjects were familiarized with the course of the imitated training and the peculiarities of the physical exercise. The HIIT consisted of four 20-second sets, with the load being 1 W per 1 kg of the body mass, according to the Wingate test protocol. During those four sets, the subjects were asked to pedal as fast as possible. The duration of the recovery period between the sets was 3 minutes. ECG was recorded continually throughout the exercise and for the first 5 minutes after it. A total of 20 subjects met the inclusion criteria and participated in the research of the third objective. Two subjects refused to continue the participation after only two sets of intensive physical exercise, and one subject performed all four sets, but experienced dizziness immediately upon the recovery after the exercise, and thus expressed the wish to discontinue his participation as well. In one subject, the recorded ECG was of exceptionally poor quality, and was therefore excluded from the analysis. Thus, in total, 16 subjects entered the research program. Results and discussion. Statistical comparisons between the values of ECG indices obtained[...].