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Heart attack? Nope, just a spin class

By Andrew Winner

 For anyone who has felt like their heart might explode after a spin class, the truth might not be that far off -- biochemically speaking, that is. New research out of Sweden has shown an hour of spinning triggers the same biochemical reactions as a heart attack. 

Research from the University of Gothenburg has shown that spin workouts and other forms of strenuous exercise can secrete the same enzymes into the bloodstream as a heart attack, increasing the possibility of a misdiagnosis. The results will be published in the Scandinavian Cardiovascular Journal.

According to study author Smita DuttaRoy, any manner of taxing physical exertion can cause a similar increase in cardiac biomarkers, including marathon running, triathlons and long-distance bike rides. However, the effect is probably as natural as it is harmless, and enzyme levels generally move back down to baseline levels within 24 hours.

Nevertheless, doctors and emergency personnel should be aware of the link between these cardiac biomarkers, as they are known, when making diagnoses and initiating treatments.

“We haven't studied whether elevated cardiac enzyme levels post-exercise are dangerous, however we don't have any reasons to believe that these levels suggest any actual damage to the heart,” DuttaRoy wrote in an e-mail. “The pattern of cardiac enzyme level elevation post-exercise with a quick normalization (within 24 hours), is different from a heart attack, where the cardiac enzymes often stay elevated for days.” 

“The increase in troponin we found after a spinning session most probably demonstrates a physiological response to exercise that we have now been able to show,” she added.

DuttaRoy’s study put ten healthy people, average age of 30, through a one-hour spin workout. Simple blood tests were done before the session, one hour after the session, and again 24 hours later. The tests showed elevated levels of the cardiac biomarker troponin T, with two participants surpassing the threshold routinely used for heart attacks. A key different is that the levels went back to normal one day later, whereas heart attack victims can see their troponin T levels stay raised for several days after the event.

In a healthy heart, troponins are involved in the contraction of the heart muscle.

What’s the best course of action? DuttaRoy advises disclosing any recent physical activity to your care provider when being treated for chest pains. It’s possible that an elevated number of cardiac biomarkers could cause a misdiagnosis.

“People should seek medical advice if they have chest pain, no matter if it is following exercise, rest or other activities,” DuttaRoy cautioned. “However, the attending physicians should be aware of that troponins can be elevated following strenuous exercise and should take that in account when assessing the patient.”