Excess exercise 'hurts the heart' and cause dangerous long-term harm, say scientists

Extreme exercise such as marathons may permanently damage the heart and trigger rhythm abnormalities, warn researchers.
They say the safe ‘upper limit’ for heart health is a maximum of an hour a day - after which there is little benefit to the individual.
A review of research evidence by US physicians says intensive training schedules and extreme endurance competitions can cause long-term harm to people’s hearts.

Damage: Excessive endurance exercise can do long-term harm to the cardiovascular system, U.S. scientists say

Activities such as marathons, iron man distance triathlons, and very long distance bicycle races may cause structural changes to the heart and large arteries, leading to lasting injury.
Lead author Dr James O’Keefe, of Saint Luke’s Hospital of Kansas City, said exercise was generally beneficial for health but could tip into becoming harmful when taken to excessive lengths.

Read more: http://www.dailymail.co.uk/health/article-2154267/Excess-exercise-hurts-heart-cause-dangerous-long-term-harm-say-scientists.html#ixzz1wv0D9dQL