Montreal - Is running a marathon good for you or can it damage the heart?
A team of researchers and runners from the Heart and Stroke Foundation have come up with a practical way of answering the question. They used data from magnetic resonance imaging (MRI) to find out what is really going on in the marathoner's heart as the kilometers pile up.
"Marathon runners can be a lot less fit than they think," Dr. Eric Larose today told the Canadian Cardiovascular Congress 2010, co-hosted by the Heart and Stroke Foundation and the Canadian Cardiovascular Society.
Lack of real aerobic fitness may directly impact the ways the heart organizes itself to survive the stress of marathon running, says Dr. Larose.
His research found that the magnitude of abnormal heart segments was more widespread and significant in a group of less fit runners. During the marathon, they had signs the heart might be at greater risk of damage than that of runners who had better training or at least had better exercise capacity.
"Without proper training, marathon running can damage your heart. Fortunately the exercise-induced injury is reversible over time," said Dr. Larose. "But it could take up to three months to completely recover."
They studied the effects using MRI measurements, which propel research beyond the traditional stethoscope as a means of estimating and measuring heart function.
The left ventricle of the heart is divided into 17 segments that make up the heart as a whole. When a segment is injured − or stressed out − during the marathon, its neighbours on either side can take over to perform the function of the damaged area. This makes the heart as a whole appear stronger and fitter than is really the case when considering each individual segment.
It also makes it practically impossible for physicians to arrive at an accurate assessment of the heart health of the marathoner when only considering the wh
|Contact: Jane-Diane Fraser|
Heart and Stroke Foundation of Canada