Heart risk for extreme cyclists?

Study suggests cardiovascular stress for endurance cyclists

by Sarah Barth   June 18, 2012  

St John Ambulance cycling first aiders 2.jpg

Extreme endurance events including cycling and running can cause cardiovascular problems, a paper in the June issue of Mayo Clinic Proceedings says.

Although moderate exercise is encouraged by doctors, excessive exertion can risk problems including atrial and ventricular arrhythmias, coronary artery calcification and diastolic dysfunction.

Endurance sports, including professional cycling, have been associated with up to a fivefold increase in the prevalence of atrial fibrillation, the Mayo report said.

It is thought that structural changes that occur in the heart during extreme exercise can cause a buildup in scar tissue over time.

“Physical exercise, though not a drug, possesses many traits of a powerful pharmacologic agent,” James H. O’Keefe, MD, lead author of the Mayo Clinic Proceedings report and a cardiologist at Saint Luke’s Hospital of Kansas City, told the American Medical Times.

“However, as with any pharmacologic agent, a safe upper-dose limit potentially exists, beyond which the adverse effects of physical exercise, such as musculoskeletal trauma and cardiovascular stress, may outweigh its benefits.”

These health scare stories regularly do the rounds, but it’s worth noting that moderate strenuous exercise, most days of the week, is almost universally endorsed by doctors for health and longevity, and outside of pro cycling even the most competitive of riders would struggle to rack up the miles required to damage their hearts.

20 user comments

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posted by seanbolton [150 posts]
18th June 2012 - 7:39


I suggest folk actually read the last sentence, because pretty much ALL of us fall in to THAT category.

Indeed, few of us have the time to do enough strenuous "extreme" activity for this to be anything more than a quirky little piece about something that concerns about 0.00000001% of the population.

And THAT is probably an overestimate Smile

.....aspiring to mediocrity Big Grin

Mr_eL_Bee's picture

posted by Mr_eL_Bee [69 posts]
18th June 2012 - 7:49


If you push your body beyond its limits you are going to cause it damage, but very few people have the will to push their bodies that far. At the end of the day not taking exercise is far more damaging.

posted by Kim [163 posts]
18th June 2012 - 9:15


I can't wait for the first person to tell me that excercise can be bad for me. I always say that I only excercise so I can eat cream cakes, McD's and Donuts constantlty and not get fat! The way that cardiac problems could affect a cyclists longevity is when some fat driver smoking a cigar has a heart attack and drives over one of us!

posted by SideBurn [896 posts]
18th June 2012 - 9:30


I read as far as 'Mayo' then my thoughts turned to Frites en Mayo, and I started to drool …

posted by ped [178 posts]
18th June 2012 - 9:44


An interesting piece of scaremongering by the Mayo Clinic.

I rowed competitively from age 17 and developed/was identified as having an arterial fibrillation (in the fom of Wolff Parkinson White Syndrome) at age 20. The cardiologist I dealt with told me at the time that sportspeople were more likely to be referred with these conditions (particulary at younger ages), but that it was likely that a section of the population were susceptable to the condition but that it never presented symptoms, or they presented when older.

I trained hard, but there were lots of people training just as hard as I did, and yet still only a very small number of people develop these conditions so there has to be more to it than just intensity of exercise. Even in those training at high intensity it is still very rare, unlike diabetes & obesity amongst inactive people.

If you catch your pulse running too fast to count, or feel lightheaded and nauseous and not-right sometimes under (or directly after) effort get it checked out. They are often quite easily fixed or controlled by drugs, especially if you are (relatively) young and healthy. My op was nothing compared to the people I shared a ward with (they were all waiting for triple bypasses, at least some of which I dare say could have been avoided by a little more intense exercise earlier in their lives).

sparrow_h's picture

posted by sparrow_h [35 posts]
18th June 2012 - 11:05


appearing soon in the Daily Mail as "Cycling Causes Heart Disease". Followed a few days later by "Health Benefits of Cycling" accompanied by a picture of Kelly Brook on a bike.



joemmo's picture

posted by joemmo [956 posts]
18th June 2012 - 11:46


What a stupid predicament.

Doesn't matter anyway, because something else will get you, probably white handlebar tape or something.

Sir Velo

Raleigh's picture

posted by Raleigh [1734 posts]
18th June 2012 - 12:50


The idea of being so gloriously fast and fit and dedicated to my sport that I might suddenly drop dead from heart-failure on a deserted mountain pass somewhere in the back of beyond appeals to me enormously. Of all the ways to break down, this is one of the better ones available.

posted by BigDummy [301 posts]
18th June 2012 - 13:06


posted by ribena [157 posts]
18th June 2012 - 13:41


Rollocks! (sorry mis-spelt that)


antonio's picture

posted by antonio [1044 posts]
18th June 2012 - 14:05


Confession time I cycle I have a tendency to cycle close to the limits of my physical ability. But of all the tumbles I have had cycling; only one can be associated with my heart condition and that was because I didn't take care of myself.
I constantly have to balance the risks to my health of cycling and of not cycling and being wise/aware about going on with my body/mind play a significant part allowing me to cycle and be healthy.
This research(?) if true would only apply in particular circumstance to particular people:
1.The person will have to be doing high physical stress endurance exercise.
2. The level at which a person can safely sustain such exercise will differ between individuals. This is due to nature and nurture
3 The degree of obsession and anxiety involved. No doubt obsession and anxiety play a role in over exercising as they do in athletic achievement. The root cause of that obsession/anxiety and the point at which they have a negative impact on overall well-being will be different for each individual.


posted by lushmiester [156 posts]
18th June 2012 - 14:46


And if it was true who cares.

posted by mattsccm [285 posts]
18th June 2012 - 15:35


We are going to die anyway so you might as well do something you enjoy.

cidermart's picture

posted by cidermart [483 posts]
18th June 2012 - 18:39


USA the country with the highest obesity levels in the world and their worried about a minute number of sportsmen overdoing it! I suggest their research money would be better spent looking for a way to lower the much larger number of obese people with cardiac problems.

The phrase “Physical exercise, though not a drug, possesses many traits of a powerful pharmacologic agent,” indicates how much notice such be taken of this load of codswallop Wink

Paul W

posted by PaulVWatts [111 posts]
18th June 2012 - 20:44


If this is so, how come cyclists aren't dying of it, instead it's some drivers who appear to doing their best to reduce cyclists numbers in the UK.

posted by northstar [1113 posts]
18th June 2012 - 21:30


I suspect that I'm not the only one who'd like to die in the saddle.

Gerard the Kiwi

GerardR's picture

posted by GerardR [88 posts]
18th June 2012 - 23:56


Personally I believe every word in the report and I shall forthwith cease all lunatic-level exercise .

Now, where does that leave me? Oh yes, precisely where I already was.


mike the bike's picture

posted by mike the bike [237 posts]
20th June 2012 - 17:38


I was also told I had Wolff-Parkinson-White Syndrome last year, but I apparently had it since birth, rather than getting it from training.
If anyone else sees their heart rate go from 185 to 245 then you should probably go for a scan, thats why I did Smile

posted by jamjam [61 posts]
21st June 2012 - 8:08


In reply to KIM.

Yes when you exercise you do damage. it happens to all of us. The body then adapts and repairs and grows stronger. It's a basic training effect. With extreme you have to watch the level of damage you do and whether the body can adapt from it. If I lifted a weight that was a little more than I was used to then I would most likely have a training effect. If a lifted a weight that was monstrously heavy from what I was used to I would have an injury or I continually trained and trained with little rest and adaption I reckon you could have problems.

Cardiovascular effects the same way. I am assuming there is no hidden hereditary problems but there is no reason why you can't reach your absolute maximum over time and with proper guidance but athletes have a clinical term for the function of there hearts (its called the athletes heart). The function and operation of a professional athletes heart does not conform to standard heart operations. Typically of the medical professionals it is deemed diseased as it does not conform to standard parametres. They do the same with pregnant women because this is not a normal operation for a female body. Its terminology, as there is clearly nothing wrong with a health pregnant female

What I find strange with this report is that is does not relate to an athletes heart. There are irregular operations but it may still be healthy. They don't define excessive exertion and within which parametres they are talking about. Is it me lifting a too heavy weight for too long or training and training and training but with little rest and adaption. There is a difference.

posted by Ciaran Patrick [119 posts]
23rd June 2012 - 17:08