Too much exercise may be bad for your heart

Toronto

Theresearchers reviewed studies that looked into the relationship between exerciseand heart problems and found that there is growing evidence that high levels ofintense exercise may be cardio toxic and promote permanent structural changesin the heart.

There is already fairly compelling evidence supporting the association betweenlong-term sports practice and increased prevalence of atrial fibrillation –abnormal heart rhythm characterised by rapid and irregular beating.

"Much of the discussion regarding the relative risks and benefits oflong-term endurance sports training is hijacked by definitive media-grabbingstatements, which has fuelled an environment in which one may be criticized foreven questioning the benefits of exercise," explained study author AndreLa Gerche from the Baker IDI Heart and Diabetes Institute, Melbourne,Australia. 

"This paper discusses the often questionable, incomplete, andcontroversial science behind the emerging concern that high levels of intenseexercise may be associated with some adverse health effects," La Gerchenoted.

The study was published in the Canadian Journal of Cardiology.

"The answers regarding the healthfulness of 'extreme' exercise are notcomplete and there are valid questions being raised," La Gerche said. 

"Given that this is a concern that affects such a large proportion ofsociety, it is something that deserves investment. The lack of largeprospective studies of persons engaged in high-volume and high-intensityexercise represents the biggest deficiency in the literature to date, and,although such work presents a logistical and financial challenge, manyquestions will remain controversies until such data emerge," La Gercheobserved.