Sekhem

Greetings Friends
There have been inquiries on this list in the past about negative health impacts of endurance sports. there's a new article that just came out in the June 2012 issue:

O'Keefe et al 2012. Potential Adverse Cardiovascular Effects from Excessive endurance exercise. Mayo Clin Proc 87(6) 587-595.

The authors suggest that chronic trining for and competeing in extreme endurance events (including 'very' long distance bicycle races) may be associated w/ transient reduction in right ventricular ejection fraction (pumping capacity of the heart), and elevation of cardiac biomarkers that indicate myocardial injury. The changes are transient, lasting 1 wk to 1 month in young healthy males. With long term repetitive injury, this process can lead to myocardial fibrosis leading to a higher risk of heart arrhythmnias, coronary artery calcification, diatolic dysfunction and increased vascular stiffness. Veteran endurance atheletes have a 5-fold increase in the prevalence of atrial fibrillation (which can lead to sudden death). Increased vascular stiffness is associated w/ hypertension.

The authors acknowledge that the process is not well understood and why some individuals seem to be susceptible to problems while others are not is not known (So I guess the warnings are 'hypothetical' rather than evidence based). The article reviews data from events that are by definition 'extreme' (competitive marathons). Who knows what happens on a long and slow ride.

Remember that people who exercise regularly have lower rates of disability and a mean life expectancy that is 7 yrs longer than inactive people. Routine exercise (e.g., running) is associated with a 19% lower risk of all-cause mortality compared w/ sedetary folks.

On a side note... we study bone metabolism in our group and have done studies on competative cyclists (Barry et al 2011 Acute calcium ingestion attenuates exercise-induced disruption of calcium homeostasis Med Sco Ports Exerc 43(4):617-623). In a recent sample of twenty-ish yr old male high-end racers- about a third had osteopenia/osteoporosis (thinning of the bones). The loss of bone calcium over the season is pretty impressive. As above, the effect is assumed to be related to the intensity of exercise. It's unknow what might be going on with Brevet riders. Under the advice of your doctor, consuming calcium during or after a ride couldn't hurt.

Bottom line...
Be careful out there and take good care of yourself!

Best Wishes

skiffrun

^

I can't tell what from above is copied from the article, and what are "Sekhem" words. I also don't know who "Sekhem" is or what he does in life, so I don't know if what might be his words have any "medical" of physiological validity or not.


However, I do know a randonneur that is also a physiologist, and quoting from his "article":

"So what kind of activities does this particular team of cardiologists believe qualify as “excessive endurance exercise? According to the article,

"'[C]hronic training for and competing in extreme endurance events such as marathons, ultramarathons, ironman distance triathlons, and very long distance bicycle races . . .'

"Cycling? In an interview, the lead researcher, James O’Keefe, mentions the Tour de France and 200-mile bicycle races as examples of excessive endurance exercise.

"Inferring from the article, it seems that for an endurance exercise regimen to qualify as “excessive,” it must be 1) almost daily, 2) hours at a time, 3) intense (racing), and 4) chronic (yearly)."

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The Tour de France and 200-mile bicycle races are NOT brevets.
Even the utlra-marathon cyclists that I know do NOT spend all day, every day, cycling. They work real-life jobs.

I'm thinking that article has caused and is causing panic among people whom do not fit the parameters of the study.


Not quite full disclosure:
I am not a medical professional. I'm an actuary.
I have a blog -- it is about cycling.
I have only once written anything close to being "actuarial" on that blog.

...Martin

unterhausen

my guess is that their sample of TdF riders and even 200 mile bike race participants was zero. But I'm too lazy to track down the article and find out. My own observations of the randonneuring population in the U.S. shows that randonneuring doesn't exactly guarantee that you will not have heart issues, some fatal. I know in my own case that randonneuring helps with my lipids, blood sugar regulation and blood pressure. So I am definitely combating the more common causes of heart disease.

ThermionicScott 

The biggest health effect I've noticed since picking up rando riding is that everyone thinks I'm nuts.

mikepwagner

Did you find anything in the article that suggested that the risk only accrues for cyclists who spend all day, every day?

I did not see that. In the conclusion, I did see a threshold that surprised me (much lower than I expected):

Here's the copy of the article I glanced at:

https://trimadnessblog.files.wordpres...yo-article.pdf

Mike

Baggins2012

There was actually a pretty robust study presented earlier this month, 50,000 plus subjects followed for 15 years. Showed a U shaped response to running. This means that with prob of death on the y axis and amount of running on the X axis, a U shape is graphed. So running lowers death rate to a point, but instead of reaching a plateau, it starts back upward with higher risk of death is higher mileage/higher speed runner vs runners with more moderate activity

Its a pretty powerful study, the O Keefe study that started this post is speculation on the mechanism of the U shaped response.

I dont find this too surprising, many,many interventions show this type of response. Take a 81mg "baby" aspirin a day, and you'll reduce your risk of heart attack. Take a gram of a aspirin a day (the amount that works great on a headache), and you'll ramp up your risk of dying of bleeding ulcer. Drink 1 glass of wine per day, and it's cardioprotective. Drink a liter a day, and you're a wino with a pickled liver.

Carbonfiberboy 

The only people I know with A-fib are life-time athletes over the age of 60 who have done endurance racing. My local cycling club has had people die on the bike. And of course there was Ed Burke. Life's only about choices, the kicker being that we can't know the consequences of our choices when we make them.

lhbernhardt

On an intuitive level, I can't help but think that riding the Tour de France or riding RAAM to win can't help but shorten your life. My motto has always been "medio tutissiumus ibis" (always take the middle path, or all things in moderation).

There was a time when ex-pro bike racers would die at age 54, pretty consistently. But I think this was due to the drugs they were taking. This was back in "the old days," before systematic drug testing.

The only negative effect I've noticed from doing long rides (double centuries, anything more than 300 km) is that my hands get numb. Might be some nerve damage. And I move my hands around the bars a lot, and shake them out every now and then. The other piece of anecdotal evidence I can offer is that I think my hair is thinning faster from doing endurance stuff, while back when I was racing, short intense efforts seemed to keep my hair growth thicker. Guess I'll have to get back into bike racing if I don't want to go bald. Just anecdotal, though.

Luis

Midnight Biker

I was also quite shocked by the insultingly low threshold, which thankfully doesn't apply to walking since for me that raises my heart rate as much as sitting at a desk, and they say nothing about sitting at a desk scarring the heart muscle. At least I have the comfort of knowing I can walk for hours on end without hurting my heart, if nothing else.

My problem is that I have to be in motion in order to feel good. Before I read this article I used to bike all day, and I hammered it. I loved it that way. I rode at a consistent pace of 16 mph, standing on my pedals a third of the time. If I wasn't at work or sleeping, I was on my bike, exploring neighborhoods, wooded trails and just enjoying in the refreshing wind on my face. I have anxiety issues, most of which are related to my health, which miraculously disappear as soon as get on a bike at ride at least 15 miles. Unfortunately, this takes more than an hour to do even at a vigorous pace. When I first read the article, the part that suggested limiting your workout time to less than one hour/day in order to stay healthy hurt the most. My warmup usually lasts about 1 hour...

So what's bad for the heart anyway? I figured I can bike a century at a pace of about 8 - 11 mph and come out of it relatively unchanged internally. Light to moderate exercise probably won't hurt you even if you do it for over the suggested time of 1 hour/day, it probably won't hurt you even if you do it for 2 or 3 hours (It seems plausible... I wish I was a doctor). I figure, as long as I am not sweaty all over, fighting to catch my breath with a heart-rate of 150 bpm the whole time, I am really not doing anything all that vigorous. And most of the time, when I'm out riding, I am not sweaty all over, fighting to catch my breath, I am actually quite comfortable. Sometimes I do get uncomfortable but only for a few minutes, definitely not the whole entire time I'm out biking. I'm 23 now and have been riding for 3 years, even if I did some extremely stupid things, like getting dehydrated and overheated on a few occasion, in these past 3 years, I think -- I hope I can still undo the damage by being more responsible from this point on. This will not deter me from biking.

I don't imagine getting tired to the point of being uncomfortable can be good for you even if it lasts only a few minutes. Like another user wrote above, medio tutissiumus ibis.

BTW, I would like to point out that atrial fibrillation does not usually lead to sudden death, that's ventricular fibrillation. Atrial fibrillation could lead to stroke.

Homeyba

You're a worry wart. You need to stop reading, go out and enjoy your life while you have it. If you're not careful, you're going to scare yourself to the point of never getting out of bed.

Midnight Biker

I was already there my friend. My entire 18th year on this earth was spent in bed with a SEVERE and I mean an out-of-this-world panic disorder and benzo addiction. It all started when I wasn't performing as well as I wanted to in college. I wanted to be perfect and when I wasn't I decided it was because I had MS or a brain aneurysm. I was delusional. Then I started getting PACs (skipped heart beats and extra heart beats) from my anxiety and I convinced myself I had a heart condition. I actually made it out of that terrible prison of worry and beat my benzo addiction and started biking to kill the anxiety. 4 years later and I'm doing quite well I think. I don't think I'll ever get that low again but sometimes these sorts of things can set me off. This series of articles did so pretty bad. But I have a good grasp of what's going on.

unterhausen

cycling may not be the right sport for people that have tendencies for hypochondria. A certain class of medical researchers likes to try to find ways that cycling is bad for you. For example, I don't know how many studies we need to show that cycling is bad for having kids. And then they went through the cycling is bad for your bone density stage. Now we are going through the cycling is bad for your heart stage. I expect to rinse and repeat the above subjects and more.

There are known bad effects on the heart of ageing endurance athletes. However, they aren't as bad as the bad effects on your heart of sitting on the couch eating moon pies and drinking RC cola.

Machka 

In my case, I already have heart disease/issues ... if I had been born prior to WWII, I would very likely have died by the age of 4 ... every year past that point is a bonus.

So I figure I might as well ride my bicycle.

Midnight Biker

So the moderation bandwagon is the best. I biked like a maniac for only 3 years and I'm only 23, I don't think I have given myself a death sentence just yet... anyway, maybe the next study they come up with will be something along the lines of my first post on this forum -- that cycling is bad for the brain. They did a study like that for running, saying that certain bio markers indicating brain injury were present in the blood of people who had just finished a long-distance run.

muu

The graphs in that Mayo article are misleading at best. The benefits 'peak' at 60min vigorous / 120min moderate, but how does it go from there? Is it a reverse parabola, is there a more gradual decrease, what makes them think this part of the data is not worth posting (insignificant? Conflicts with their other finds? etc). There's obviously risks involved, but you should absolutely not be thinking that if you go over their supposed "limit" that you're suddenly going to explode.

I recall seeing the "cycle commuting is bad for you because of the bad air you breathe" stage, which was then countered by findings that air circulating inside cars is far, far worse for you than what's outside.

Machka 

If the longest ride you've ever done was 68 miles, as you stated in the General Cycling forum, I doubt you have really "biked like a maniac", and you're not a long distance cyclist yet.

But yes, you have given yourself a death sentence ... or rather, your parents did. Sorry to break it to you ... you are going to die.

ttusomeone

Dude, I really hope you are trolling. If not, based on your previous posts, you should stop cycling immediately. In fact, if I were you I wouldn't leave the house without a helmet, gas mask, and full body armor to help protect you from bumps, fumes, and other worldly hazards. Not trying to be mean, but common sense dictates the benefits gained from an active lifestyle (biking, running, etc.) greatly outweighs the associated risks and definitely beats the health risks associated with a sedentary lifestyle.

Midnight Biker

Of course LOL.

contango 

Sounds like a good philosophy. I'd rather enjoy my life than spend it worrying about how it will end.

contango 

Yep... after many years of sitting on my rear end and eating too much I was fat and unfit. Cycling a lot means I'm nowhere near as fat and vastly fitter, to the point that if I see another cyclist on the road I'm faster than they are probably 80% of the time (three years ago I was faster than the other guy maybe 1% of the time, on a good day). My resting pulse has dropped from the 80s to somewhere around 60 and sometimes lower still.

Having been in a place where I had to catch my breath after climbing a single flight of stairs and pouring sweat after walking half a mile I'll take the risks of cycling over the risks of not cycling in a (slower) heartbeat.

unterhausen

I didn't ride as much after PBP and gained some weight. My doctor was all over me since I gained weight since the last time I had a physical 2 years ago. Of course, when I had a physical the previous time I had just finished an SR series, so I was way down on weight. I was thinking if a fairly fit person like me is in danger of having heart problems, think of all the people that can't actually ride halfway across France. And back.

rogerstg

+1
I'm sitting here in week 4 recovering from direct hit by a car going ~40 mph (4 fractured vertebrae and lots of bruising).
I can't wait to be well enough to get back on my bike.

slowride454

i think i read in one of my wife's books that pregnancy shrinks a woman's brain. reproducing must be bad for you also. This all sounds like a pile of BS. Any pure athlete is using up their body. Pro football players die of various ailments early too. So running into each other at full speed must be bad too? Duh

The one thing I've noticed from riding longer distance is my hand strength is greatly diminished and I've only been back into riding for about a year.

JohnL. Nelson

I would be more interested in the effect of endurance training and extreme level on the microcirculation which are the tiniest vessels involved in the exchange of nutrients and waste processes. More and more evidence suggests that integrity of the microcirculation and modalities to improve microcirculation are not only healthy but perhaps a blueprint for managing chronic disease states...

Flounce

From what I've read in the past, the negative effect of cycling on bone density - increasing rates of osteoporosis - is fairly definitive and well-accepted.

The cardiovascular effects I know nothing about. I'm a physician, but this area is not my expertise. I will say that I would not at all be surprised if my 14+ hour rides are detrimental to my health. I know one cyclist who has been doing around 10,000 miles a year for a decade or so, healthy looking fit guy in his mid 50s, who had a heart attack a few years ago. Completely anecdotal, "N of one" etc.