High-intensity interval exercise is safe for stable heart transplant patients, a new study reveals.

Researchers from Denmark have found that high-intensity workout can help heart transplant patients gain better control of their blood pressure.

The new study findings bring good news for people training for the Transplant Games of America, whose most recent event was held earlier this month in Houston.

Previous research has maintained that people with heart diseases or those who have undergone heart transplant must restrict themselves to moderate physical activity. The latest study shows that under some conditions, people with heart problems can benefit from high-intensity workouts.

The study was based on data from 16 stable heart transplant recipients who had been living with their new heart for about a year. The researchers compared effects of high-intensity training versus moderate training in these participants.

The researchers found some key benefits of high-intensity training:

  • VO2 max, or maximal oxygen uptake, rose by 17 percent in high intensity exercise group while it was 10 percent in people who continued moderate exercise.
  • Systolic blood pressure decreased in high-intensity exercise group
  • Peak heart rate improved in people who were more active than others.

"Today, people who have been given a new heart experience increased physical function, quality of life, and overall life span; however, most patients continue to have limitations in their physical function and reduced quality of life compared to the general population due to side-effects from anti-rejection medications and because heart rate regulation is impaired after heart transplantation," said  Christian Dall, PhD fellow, MSc, of the Bispebjerg Hospital at the University of Copenhagen, Denmark.

"The impaired heart rate response has been considered a hindrance for more demanding high-intensity training, but this new study documents that stable heart transplant recipients benefit from this type of training more than from the moderate training that has been recommended so far. Importantly, the training is also safe and well received by patients," Dall added in a news release.

The study is published in the American Journal of Transplantation.