High-intensity interval training (HIIT) is frequently used in sports training. The effects on cardiorespiratory and muscle systems have led scientists to consider its application in the field of cardiovascular diseases. The objective of this review is to report the effects and interest of HIIT in patients with coronary artery disease (CAD) and heart failure (HF), as well as in persons with high cardiovascular risk. A non-systematic review of the literature in the MEDLINE database using keywords 'exercise', 'high-intensity interval training', 'interval training', 'coronary artery disease', 'coronary heart disease', 'chronic heart failure' and 'metabolic syndrome' was performed. We selected articles concerning basic science research, physiological research, and randomized or non-randomized interventional clinical trials published in English. To summarize, HIIT appears safe and better tolerated by patients than moderate-intensity continuous exercise (MICE). HIIT gives rise to many short- and long-term central and peripheral adaptations in these populations. In stable and selected patients, it induces substantial clinical improvements, superior to those achieved by MICE, including beneficial effects on several important prognostic factors (peak oxygen uptake, ventricular function, endothelial function), as well as improving quality of life. HIIT appears to be a safe and effective alternative for the rehabilitation of patients with CAD and HF. It may also assist in improving adherence to exercise training. Larger randomized interventional studies are now necessary to improve the indications for this therapy in different populations.

No abstract

Patients with cardiovascular disease show autonomic dysfunction, including sympathetic activation and vagal withdrawal, which leads to fatal events. This review aims to place sympathovagal balance as an essential element to be considered in management for cardiovascular disease patients who benefit from a cardiac rehabilitation program. Many studies showed that exercise training, as non-pharmacologic treatment, plays an important role in enhancing sympathovagal balance and could normalize levels of markers of sympathetic flow measured by microneurography, heart rate variability or plasma catecholamine levels. This alteration positively affects prognosis with cardiovascular disease. In general, cardiac rehabilitation programs include moderate-intensity and continuous aerobic exercise. Other forms of activities such as high-intensity interval training, breathing exercises, relaxation and transcutaneous electrical stimulation can improve sympathovagal balance and should be implemented in cardiac rehabilitation programs. Currently, the exercise training programs in cardiac rehabilitation are individualized to optimize health outcomes. The sports science concept of the heart rate variability (HRV)-vagal index used to manage exercise sessions (for a goal of performance) could be implemented in cardiac rehabilitation to improve cardiovascular fitness and autonomic nervous system function.

when considering physiological responses, safety, and perceived exertion, the HIIE protocol seemed to be well tolerated and more efficient in this group of stable CHD patients.

No abstract

High intensity interval training has been shown to be more effective than moderate intensity continuous training for improving maximal oxygen uptake (VO(2max)) in patients with coronary heart disease (CHD). However, no evidence supports the prescription of one specific protocol of high intensity interval exercise (HIIE) in this population. The purpose of this study was to compare the acute cardiopulmonary responses with four different single bouts of HIIE in order to identify the most optimal one in CHD patients. Nineteen stable CHD patients (17 males, 2 females, 65 +/- 8 years) performed four different bouts of HIIE, all with exercise phases at 100% of maximal aerobic power (MAP), but which varied in interval duration (15 s for mode A and B and 60 s for mode C and D) and type of recovery (0% of MAP for modes A and C and 50% of MAP for modes B and D). A passive recovery phase resulted in a longer time to exhaustion compared to an active recovery phase, irrespective of the duration of the exercise and recovery periods (15 or 60 s, p < 0.05). Time to exhaustion also tended to be higher with mode A relative to mode C (p = 0.06). Despite differences in time to exhaustion between modes, time spent at a high percentage of VO(2max) was similar between HIIE modes except for less time spent above 90 and 95% of VO(2max) for mode C when compared with modes B and D. When considering perceived exertion, patient comfort and time spent above 80% of VO(2max), mode A appeared to be the optimal HIIE session for these coronary patients.

We demonstrate that a single session of HIIE improves autonomic profile of CHF patients, leading to significant reductions of HR and arrhythmic events in a 24-h posttraining period. Cardioprotective effects of HIIE in CHF patients need to be confirmed in a larger study population and on a long-term basis.

No abstract