Originally Posted by
merlinextraligh
Until you hit the point of diminishing returns, and you begin to get no benefit from more exercise, and then actually have negative return.
The J Curve of Exercising.
Exercise, over-indulgence and atrial fibrillation ? seeing the obvious
The study referred to your in link was based on 150 minutes of moderate exercise a week (defined as brisk walking). It doesn't address the potential negative effects of years of intense race training.
That's an interesting link. If I'm reading that correctly, the commenter says that Afib probabilities start to increase at ~2000 hours total lifetime exercise. Thing is, most riders who train for high fitness put in 300-400 hours/year just on the bike. I have 170 hours so far this year, just on our tandem, and we don't put in near the hours that many of our riding friends do. Looking at total exercise time including weights, hiking, and cross training, it comes to 319 hours so far this year.
Given that I started riding a lot again 20 years ago, that's something on the order of 10,000 hours right there. Then there's 20 years of alpine and XC skiing, being on a Nordic ski team, climbing, biking from 8 years old through college, running a few miles a week from 12 to 25, and hiking. Man, that's a lot of hours. I think many of us on this forum have similar histories, or will if they keep at it until they're as old as I am. And I'm not quitting. Like Rudy, I think being old is still 10 years away. Heck, I'm still skiing alpine and this year Stevens Pass will finally sell me a full season pass for $99.
So while I've been careful all my life to limit my hours of high end, I think something is fishy somewhere.