Interval Training Improves Heart Function in Patients with Congestive Heart Failure

In a study published inCirculation, investigators disproved the belief that physical exercise leads to harmful ventricular enlargement in patients with congestive heart failure.

Congestive heart failure is one of the most common causes of death in industrialized countries, and before the current technologies developed, the condition had a poor prognosis.

“Previously, congestive heart failure was primarily treated with drugs,” said author Martin Halle. “The range of treatments was expanded by the use of cardiac pacemakers to optimize heart muscle contraction and the implantation of defibrillators intended to improve myocardial function and prevent sudden cardiac death due to arrhythmia.”

Individuals withheart failurewere forbidden to engage in physical training because of the belief that it would cause more damage to the heart. In recent years, however, study results have shown that adding physical training can improve endurance and reduce the risk of rehospitalization caused by worsening of symptoms.

For the study, conducted in 9 European centers between 2009 and 2014, investigators examined the effects of different forms of physical training on a damaged heart.

“With this study, we were able to prove that exercise training does not deteriorate dilatation and function of the heart and seems to be safe,” Halle said.

Included in the study were 261 patients with heart failure who were assigned to 3 groups. Over the course of 52 weeks, the participants underwent training of different intensities. Initially, all 3 groups underwent supervised training for 3 months, and it was recommended that they continue the intervention for another 9 months.

The results of the study showed that patients who participated in 12 weeks of regular supervised exercise had better effects compared with those who just received a recommendation to train on their own.

“We actually observed a decrease in the size of the left ventricle, and with it, an improvement in pumping function. This increased their physical fitness,” Halle said.

There were no significant differences observed between a new program of interval training at high intensity and a standard therapy with continuous exercise at moderate intensity.

“We actually observed that this training revealed the best improvements and that not exercising was significantly worse regarding pump function and hospitalization,” Halle said.

The authors offered this practical definition of “moderate” training: approximately 100 steps per minute or 3000 steps in 20 minutes.

“Overall, this new study underscores how advisable regular physical training at moderate intensity is for patients with systolic heart failure,” Halle concluded. “But I would rather discourage high intensity exercise until larger studies will prove this to be as safe.”