A comparison of high intensity interval training with circuit training in a short-term cardiac rehabilitation programme for patients with chronic heart failure

High intensity interval exercise may be a more effective training method than moderateintensity exercise more commonly applied in cardiac rehabilitation. This randomisedcontrolled trial compared the effects of high intensity interval training with moderateintensity circuit training on exercise tolerance and quality of life in patients with chronic heartfailure. Twenty six patients with systolic heart failure (left ventricular ejection fraction 15-40%, New York Heart Association class II-III, age 62-87 years) were randomly assigned tocircuit training (n=13) or high intensity interval training (n=13) during a 6 week cardiacrehabilitation programme. At baseline and on completion peak oxygen consumption(VO2peak), oxygen consumption at ventilatory threshold (VT), ventilatory efficiency anddisease specific quality of life were assessed. There was a significant increase in VO2peak aftertraining in the circuit group only (0.97 ml.kg-1.min-1 P=0.021). Both groups showedsignificant improvements in VT (circuit 0.55 ml.kg-1.min-1 P =0.050; interval 1.70 ml.kg-1.min-1 P =0.006) and in quality of life (circuit -7 points P=0.017; interval -5 points P=0.050).There were no significant differences between the two training methods. High intensityinterval exercise offers an alternative training mode for improving submaximal exercisetolerance and quality of life in patients with chronic heart failure. However, theimprovements did not match those reported in studies using more frequent and longerduration training interventions.