Study: Better Athletes Have More Heart Arrhythmias

Irregular heartbeats were more common among the top performers in an extreme cross-country ski race.
More
RTXC7RSmain.jpg
Athletes compete in the world's longest cross-country ski race. [Reuters]

PROBLEM: Extreme endurance athletes, like long-distance runners, bikers, and even cross-country skiers, tend to have enlarged hearts. Also known as "Athlete's Heart," the condition may be associated with an increased risk of heart problems. Within this already elite group, are those who push themselves the hardest even more at risk?

METHODOLOGY: Researchers based in Uppsala and Stockholm studied almost 53,000 cross-country skiers (mostly men) who managed to complete the Vasaloppet -- the longest cross-country ski race in the world -- between 1989 and 1998, and followed up with them through 2005 using national health registry data. They grouped the participants into quartiles based on the number of races they'd completed and their finishing time, excluded anyone with a history of cardiovascular disease, and controlled for age and other factors.

RESULTS: Those who completed five or more races in a ten-year period, or who placed among the top 25 percent of finishers, increased their risk of developing some form of cardiac arrhythmia -- either an irregular, abnormally fast, or too slow heartbeat -- by 30 percent. 

Between each quartile for the number of races completed (from one to five or more), the risk of arrhythmia increased by 10 percent. A similar trend occurred as finishing time decreased, although this did not reach statistical significance. 

IMPLICATIONS: The Vasaloppet's participants, compared, to "average Swedes," have "lower incidence of physical and mental illness, tobacco consumption, fat intake, and higher fiber consumption." But compared to one another, the top performers were more likely to experience heart irregularities than other, still-extreme-but-less-so athletes.

The researchers didn't find any evidence for the athletes being at an increased risk of the most serious forms of heart failure, like cardiac arrest, and don't necessarily recommend that people cut back on the number of 90 kilometer cross-country megaraces they compete in. Nonetheless, the correlation between increased physical activity and increased heart health may not be as straightforward as we'd like to assume. 


The full study, "Risk of arrhythmias in 52 755 long-distance cross-country skiers: a cohort study" is published in the European Heart Journal.

Jump to comments
Presented by

Lindsay Abrams is an assistant editor at Salon and a former writer and producer for The Atlantic's Health Channel.

Get Today's Top Stories in Your Inbox (preview)

Why Do People Love Times Square?

A filmmaker asks New Yorkers and tourists about the allure of Broadway's iconic plaza


Join the Discussion

After you comment, click Post. If you’re not already logged in you will be asked to log in or register. blog comments powered by Disqus

Video

Why Do People Love Times Square?

A filmmaker asks New Yorkers and tourists about the allure of Broadway's iconic plaza

Video

A Time-Lapse of Alaska's Northern Lights

The beauty of aurora borealis, as seen from America's last frontier

Video

What Do You Wish You Learned in College?

Ivy League academics reveal their undergrad regrets

Video

Famous Movies, Reimagined

From Apocalypse Now to The Lord of the Rings, this clever video puts a new spin on Hollywood's greatest hits.

Video

What Is a City?

Cities are like nothing else on Earth.

Writers

Up
Down

More in Health

Just In