Originally Posted by Null66

It's remarkably reliable indicator as it is released when heart muscle DIES... Also they were able to directly observe cardiac muscle scaring... pretty definitive.

But the population was special. Very rare air people. World class competitors.

Originally Posted by RollCNY

You can take this for what you want, or do some research, but endurance exercise does get tied in to heart failure in a way you would never expect: sleep apnea. Some triathlon sites can help you find information, as can Mr. Google.

Everyone thinks that apnea only affects overweight people who don't exercise, and the common solution offered for sleep apnea is lose weight and exercise. However, nothing prevents thin and in shape people from having it for other reasons.

How does sleep apnea do heart damage? It really doesn't, but it prevents the heart from repairing damage done by long endurance effort. The way every muscle works is that you harm it by use, and it rebuilds with rest. Sleep apnea prevents the rebuilding. So your heart ever so slowly gets weaker and weaker, until eventual failure. This is not clogged arteries, but failure of the muscle.

Some of the benefits of endurance training worsen the impact. We train our muscles to use oxygen quickly, with low resting respiration and heart rates. So when an apnea occurs, we go longer before attempting another breath, while our muscles burn up the available Oxygen. If you are well trained, your blood oxygen saturation can fall below 90% (the threshhold for issues) Very quickly. The most typical sleep apnea sign, loud snoring may not occur.

I am not saying everyone has sleep apnea, and I am not saying endurance cycling gives it to you. But if you have it and if you are doing significant endurance events (which a century is NOT), you are risking your heart. Talk to any Pulmonologist. They will first discount it, thinking of the majority of patients they see, and if they think about it, you will see the light go on.

How do I know any of this? I got diagnosed with sleep apnea, and started researching like mad, and talking to pulmonologists, and then finding the articles about triathletes and marathoners who die in their sleep of heart failure. And it isn't me assuming they had apnea, but researchers starting to build the link. I was fortunate that my wife, an RN, pointed out that I stop breathing at night. I figured she was full of crap, but I wore an oxygen sensor, and thought all the results were rubbish, until I fixed it. What a difference.

Sorry. Long post. Centuries aren't hurting you. In my experience, certain conditions can translate to heart damage, but not general cycling.

Originally Posted by RollCNY

Mine is classified as mixed (which means some central and some obstructive), but positional obstructive is the primary problem. What does that mean? When I sleep on my back, my throat closes enough to restrict air flow. This could be an obstruction from the palette, or just relaxed throat muscles. When I sleep on my side, the only issue becomes central, and occurs at a rate deemed normal. So I manage mine by side sleeping.

I think sleep apnea gets ignored or overlooked often. And like any US medical issue, once you get diagnosed, you are in for the railroad route to a standard solution, which is CPAP. In my case, I pushed to see all of the data, had a good Pulmonology NP to work with, and came up with a solution that I would actually implement. When I asked what the specific reason was for the back sleeping issue, you get into testing issues: sleep studies make confirming the apneas easy, but seeing the mechanism would involve internal scanning on a sleeping, relaxed patient. So every case of sleep apnea is best solved by CPAP. Even when it isn't.

Originally Posted by RollCNY

....
How do I know any of this? I got diagnosed with sleep apnea, and started researching like mad, and talking to pulmonologists, and then finding the articles about triathletes and marathoners who die in their sleep of heart failure. And it isn't me assuming they had apnea, but researchers starting to build the link. I was fortunate that my wife, an RN, pointed out that I stop breathing at night. I figured she was full of crap, but I wore an oxygen sensor, and thought all the results were rubbish, until I fixed it. What a difference. ...

Originally Posted by RollCNY

....And your "links don't exist until peer review and publishing" argument is, in my opinion, false. ....Thi

Originally Posted by osteoclast

Ok....sleep apnea is usually (it can be central) obstructive sleep apnea (OSA). One doesn't "stop breathing" per se, one simply obstructs the airway. Snoring is simply a partially obstructed airway.

These are degrees of OSA. Probably > 50% males over 50 have a degree of OSA.

OSA is associated with all kinds of cardiovascular events, fatal and non fatal. If significant it should be treated. Yes, weight loss and exercise can be effective and yes CPAP (continuous positive airway pressure) solves the obstructive problem.

Heart failure caused by OSA is at the far, far, far end of the spectrum; it occurs in untreated Pickwickian type, OSA patients.

The extreme endurance athlete is unlikely, not impossible, but unlikely to have OSA. There are craniofacial abnormalities that can result in OSA.

Unless RollCNY can point to something in a peer reviewed medical journal to the contrary, the link between high intensity exercise, OSA and heart failure resulting in death doesn't exist.

Originally Posted by Dudelsack

Down boy. I was the one who asked for the info. BTW, how do you know extreme endurance athletes are very unlikely to have (nonobstructive) sleep apnea? Has it ever been studied?

Originally Posted by mprelaw

Fixx was obese and a two pack a day smoker for quite a few years before he took up running in his mid-30s. His autopsy disclosed three arteries with substantial blockage, from 70% to 95%. He also had a genetic history (father died of a heart attack at age 43), and an enlarged heart, which his autopsy also disclosed. Not the best example for people who cite the "dangers" of strenuous aerobic activity.

Originally Posted by Myosmith

As some of you may know, I recently had a mild heart attack at age 49. I've already heard through the grape vine of people making comments like "see, all that bicycle riding and losing all that weight didn't do him a bit of good". On the contrary, it may have save my life. I didn't do myself any favors in my younger years. My diet was atrocious, I was very overweight, and though I was strong my cardiovascular fitness left a lot to be desired. Add to that a big family history on both sides of both men and women who suffered heart attacks and died of cardiovascular disease at an early age. I'm lucky that my heart attack was very mild with "no significant damage" and my recovery was fast and appears complete. I may still die from heart disease someday, but it won't be because I rode my bicycle too much.