October 23, 2001 – Running a marathon can trigger a series of physical signs that are potentially heart risky, even in perfectly fit runners. This is what we learn from a new study published in theAmerican Journal of Cardiology. The researchers observed a phenomenon of blood clotting occurring 24 hours after the race.
For their study, they followed a group of 80 doctors who had already participated in several marathons. The subjects, averaging 47 years old, had no history of smoking or coronary heart disease. They first took three blood samples from the runners: the day before the race, a few hours after the race and the following morning. The researchers found that the blood balance was maintained before and immediately after the race, while the next morning they noted an imbalance in the coagulation and inflammation factors known to be triggers for a heart attack.
One of the troubling facts of the study came when the researchers performed a test usually used in emergency rooms to detect heart conditions. Creatine kinase-MB (a muscle enzyme) markers indicated a “positive” result while the subjects did not show any coronary damage. An earlier study1, conducted with a group of marathon runners, reports this false positive problem in the analysis of the results. It appears that the elevated creatine kinase-MB level results from skeletal muscle damage and not heart muscle damage, since troponin markers, only detected in severe cases of heart attack, remained normal. Despite these factors, no severe cardiovascular events occurred during or after the marathon. Researchers believe that high levels of clotting and inflammation factors increase the risk of cardiovascular events, but there must be some other physical sign to trigger a heart attack, for example, the presence of cardiac arrhythmia or heart attack. atherosclerotic plaque.
Cases of sudden death following strenuous exercise are rather rare and occur in people who already have a condition that has been exacerbated by too much energy expenditure. It is true that running carries risks, but that does not mean to stop all physical activity. It is important to know that running the marathon does not protect us from cardiovascular accidents. Thus, studies have shown that the beneficial effects of exercise diminish as the intensity and duration of the activity are increased and that excessive training slows down the defense mechanisms of the immune system, increasing the risk of disease.
Researchers therefore encourage young people under 30 to continue their marathon training, but for those 30 and over, they advise to be cautious. Finally, they recommend taking low doses of aspirin and seeing a doctor to assess whether taking statins, a drug that reduces the risk of heart attack, is an appropriate choice.
Monique Lalancette – PasseportSanté.net
According to InteliHealth, October 17, 2001
1. Siegel AJ, Sholar M, Yang J, Dhanak E, Lewandrowski KB. Elevated serum cardiac markers in asymptomatic marathon runners after competition: is the myocardium stunned?Cardiology 1997 Nov-Dec; 88 (6): 487-91.
