New research from the University of Alberta shows that exercise can dramatically improve cardio fitness for heart transplant patients, which may increase a recipient's lifespan.
Currently the average heart transplant patient will live for 10 years after surgery.
Researchers examined the effects of exercise training on heart, blood vessel, muscle function and overall fitness on long-term recipients.
Twenty one of the 43 people in the study didn't exercise while 22 were put on a 12-week exercise program.
The study found that exercise improved cardio-respiratory fitness, muscle mass and maximal strength, Dr. Mark Haykowsky, a professor in the faculty of rehabilitation medicine at the U of A, said on Tuesday.
Cardio-respiratory fitness in transplant recipients is 30 to 50 per cent lower than in non-recipients their age, Haykowsky said.
"We know your overall fitness is a better predictor of future mortality or death, so it's important that we maintain a certain level of fitness for our heart transplant recipients," he said.
Dwight Kroening, 49, of Edmonton took part in the study, and is considered an example of the positive effects of exercise on a transplanted heart, Haykowsky said.
In 1985, Kroening was diagnosed with an enlarged heart and doctors expected he would die in a matter of months.
Kroening underwent heart transplant surgery and resumed an active lifestyle just days after the surgery, despite the thinking at that time.
"We are told that transplanted hearts, those who are recipients, cannot do anaerobic activity which are sprints and things," Kroening said Tuesday.
Last year Kroening became the first heart transplant recipient to complete the Ironman race in Penticton, B.C., a triathlon that includes a 3.8 km swim, 180 km cycle, and 42.2 km run.
"He's the fittest heart transplant [recipient] alive, there's no other person who has the fitness that he has, especially nearly 24 years after his surgery, it's just unheard of," Haykowsky said.
It took Kroening 15 hours to complete the race.
"The most thrilling experience I've ever had in my life was running across the finish line and hearing the cheer of the crowd and hearing the commentator say 'You are an iron man,'" Kroening said.
He is making plans to compete in another triathlon next year to mark the 25th anniversary of his heart transplant surgery.