Study: Vigorous exercise does not appear harmful in those with hypertrophic cardiomyopathy

3D rendering of a male jogger with a heart problem.

Vigorous exercise does not appear to increase the risk of death or life-threatening arrhythmia for people with hypertrophic cardiomyopathy (HCM), according to a study supported by the NHLBI and published in JAMA Cardiology. 

HCM is a rare, inherited disorder that causes the heart muscle to become thick and enlarged and affects 1 in 500 people worldwide. It has been associated with sudden cardiac death in young athletes and other young people. However, the study found that people with the disease who exercise vigorously are no more likely to die or experience severe cardiac events than those who exercised moderately or not at all. 

The observational study, the largest and most extensive to explore the relationship between HCM and exercise, questions restrictions from exercise that are often recommended for anyone who has the disease.  

For the study, the researchers recruited 1,660 people who either had HCM or the gene for HCM but had not yet manifested the disease (8% of the total). The researchers found that 77 participants, or 1.5% per year, who reported exercising vigorously died or had severe cardiac events – the same percentage as those who exercised moderately or described themselves as sedentary.   

“This finding is significant and provides a measure of reassurance that exercise may be safe for persons with HCM,” said Patrice Desvigne-Nickens, M.D., a medical officer in the Heart Failure and Arrhythmias Branch in NHLBI’s Division of Cardiovascular Sciences. “However, we stress that individuals with the condition should not be exercising until they’ve first had an evaluation by a provider with expertise in HCM about their overall risk of sudden cardiac death. It is important to know that all patients with HCM could potentially be at risk for sudden death.”