Wednesday, December 14, 2011

Resistance exercise does harm the heart

       Athletes marathon, triathlon or cycling downhill should closely monitor their hearts.They have come to light the latest scientific evidence, which demonstrate that the long-term intensive sport it self can cause damage to the right ventricle (one of thefour chambers of the heart that receives deoxygenated blood from the right atrium and pumps outside the organ through the pulmonary artery) in some of them.

       André LaGerche, University of Melbourne (Australia), and lead author of the research, confirms: "We know that our work can not be extrapolated to the entire world, as to claim that intense exercise is not healthy. data do not support this premise. However, the findings suggest that some athletes may be born with a susceptibility to cardiac damage as a result of endurance sport practice sustained over time. "

         The research, published in the latest European Heart journal, sheds some more lightto a heated debate over the past two decades: the heart risks of elite athletes. In fact, recently, a group of researchers led by scientists at the Hospital Clinic of Barcelona, ​​in collaboration with the Montreal Heart Institute (Quebec, Canada), an essaypublished in 'Circulation', this time in mice, finding that the resistance exercisecontinued for years can cause changes in the structure creating a substrate forcardiac arrhythmias.

      Josep Brugada, medical director of the Hospital Clinic and one of the authors of that investigation, admits: "Neither the people nor the medical community have admitted for years that the sport's elite could lead to health problems. It was a taboo subject, because partly because it seemed that one could not say anything against the exercise, on the other hand something that we all know what that is recommended. However, evidence has been accumulated and we know that the obsession with the sport can be harmful. in fact, as with everything, mustbe must be maintained a balance. You can not take the body to the limit. "

Great Athletes

          In the new study, researchers recruited 40 elite Australian athletes who were planning to participate in one of four local events of endurance sports (marathon, cycling,skiing, triathlon and ultratriatlón).

All of them met certain criteria: they trained more than 10 hours per week, had been successful in previous competitions, had no symptoms and no cardiac risk factors, nor echocardiography showed alterations during which they practiced.

        To carry out the research, the scientists analyzed the athletes in three specific times: during the two and three weeks before the race, immediately after it, and between six and 11 days after participation, when athletes were already practicing minimal training.
To do this were submitted to magnetic resonance imaging (MRI), blood tests (before and after the competition) and echocardiography at the three mentioned above.

The data show that immediately after the sporting event, the heart of the athletes had changed: it had a larger volume and right ventricular function was decreased.
"As blood levels of B-type natriuretic peptide (BNP, its acronym in English), which is secreted by the ventricles in response to excessive stretching of cardiac muscle cells, the data show that were increased," says the trial .
It insists that although ventricular function was recovered in most athletes a week of competition, five of them (those who had spent more time training and competing), MRI detected signs of scarring (fibrosis heart ).

Early Diagnosis
"Moderate exercise is an important therapy for cardiovascular disease, but its effectson health when practiced intensively are less well defined. We have shown thatintense endurance exercise causes a reduction in right ventricular function that increases with the duration of the race and correlates with the increase in biomarkers of cardiac damage. by contrast, the left ventricle is not altered in any way ", adds the scientist LaGerche.

     The expert admits: "We now know that the intense sport increases the risk of some arrhythmias, but do not know the mechanisms by which increases the risk, although we know that the right ventricle is heavily involved . We need now to understand the changes that occur in the short termin the left heart ventricle and study the potential links between this transformation and the increased probability of arrhythmias in athletes. "

        Meanwhile, Dr. Brugada think it is absolutely necessary to make early diagnosis ofthese arrhythmias in athletes. "We know what happens to the excess of sport, a fact well documented in the Nordic skiers. But we do not know what athletes are going to suffer the consequences of their efforts. Therefore it is necessary to follow them all over term, in order to catch any anomaly. "

          On this point is in total agreement that advises Australian researcher also that athletes be alert to any symptoms. "There are no fixed rules that make us suspect theexistence of a problem, so that the athlete should be vigilant. If you notice that when he trains his performance has declined or increased heart rate at rest, both of which may mean that the heart needs more time to recover. We still need to work hard inthis field to know what is really happening. "

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