Afib, exercise, and carbo loading

[Frank Krygowski]

I just happened on this blog post by Grant Peterson of Rivendell Bikes.
He's previously noted the correlation between Atrial Fibrillation and
long duration, high intensity aerobic exercise. I've read at least on
study that found that correlation. I've gathered that some people here
have suffered Afib, as have some of my cycling friends.

Since the original blog post, Grant has appended (at the top) an email
from Peter White (seller of good headlights and dynamos). Peter says he
found his own Afib was triggered by consumption of simple carbohydrates.
He wonders if the correlation isn't Afib with exercise; instead, if
it's Afib with carbo loading.

http://rivbike.tumblr.com/


--
- Frank Krygowski

[cycl...@gmail.com]

I have limited my riding with groups because they are ALWAYS racing one another and just trying to keep up can put too many people over the limit. They think of me as strange for either riding drag or not passing the person I come up on rapidly. I really find the idea of 70 year old men racing each other any time other than in an actual race stupid and disgusting.

[Duane]

Different strokes. My club has enough groups that I can find one to
ride with that suits me. The ones that don't suit me are not
necessarily stupid and disgusting. Some of the ones that are racing are
training for races.

What's stupid is joining a group that wants to race when you don't want
to race.

[(PeteCresswell)]

Per Frank Krygowski:

> I've read at least on
>study that found that correlation. I've gathered that some people here
>have suffered Afib, as have some of my cycling friends.

Have managed to provoke afib once by hard exercise and had it come on
several times for no apparent reason - maybe leaving diet as an
explanation.

Exercise-wise, my usual workouts have been an hour at 85-90 percent of
my max heart rate (220-Age).

The one that seems to have provoked an afib onset was forty-five minutes
at 85-90% and then 15 minutes at 90-95%. But one complicating factor
was that onset of afib did not happen until several hours after the
workout.

Just the other day I tried 45 minutes at 85-90 and then five minutes at
90-95. The little hand-held single-electrode ECG thing I use didn't
call it afib, but "Uncategorized".... but the trace clearly looked
funky.

I would be grateful to hear from anybody else who is seeing a
relationship between exercise and afib.
--
Pete Cresswell

[jbeattie]

On Wednesday, November 16, 2016 at 8:55:34 AM UTC-8, Frank Krygowski wrote:

http://velonews.competitor.com/cycling-extremes (mostly about other exercise induced heart conditions):

As for electrical abnormalities, the data speaks for itself. Long-term endurance exercise results in a five-fold increase in the risk of developing AF. A review of the relevant research finds many small studies that correlate long-term sports activity with AF (incidentally, Robert Gesink of Lotto-JumboNL had surgery in May 2014 for atrial fibrillation and has returned to the sport). Though none is conclusive, collectively they indicate a pattern: “Younger patients with a lower cumulative dose of exercise have lower AF risk. Older patients with higher dosages of exercise have higher AF risk,” Mandrola said.

“[People] criticize the studies that have been done that make this association. And they have a point: Each of the studies, individually, has flaws. They’re from one center, they include small numbers of athletes, and there’s selection bias. But taken together — there’s maybe ten to 20 single-center studies that show this association. If you put all that evidence together, there’s reason to believe that endurance athletes can develop AF.”

Perhaps the most influential study on mechanisms of AF in athletes comes from the study of rats and the effects of endurance exercise on the atria, conducted by a group of Spanish researchers and published in the journal Circulation in 2010. Rats were run one hour per day, five days a week, for up to 16 weeks. And they paid. Compared with sedentary controls, the exercised rats displayed evidence of damage, things such as enhanced vagal tone, atrial dilation, atrial fibrosis, and vulnerability to pacing-induced AF. Detraining the rats quickly led to a reduction in the vulnerability of AF, but not structural changes. Fibrosis and left atrial dilation remained after the rats stopped exercising. Is this what is happening inside your chest when you repeatedly go out and ride your bike, before work, after work, and every weekend in the summer?


Read more at http://velonews.competitor.com/cycling-extremes#bGm3ivayVfo07BBI.99


So I drop dead. Meh. -- Jay Beattie.

[Frank Krygowski]

Maybe dropping dead isn't the worst part. In contrast to Grant
Peterson's article, I was told the major risk was a stroke. While a
stroke can kill instantaneously, it can also cause a person to live as
an invalid, with a really lousy quality of life. :-/

I won't have time to read your links for a while, but regarding "five
fold increase in the risk of developing AF": The book _Bad Science_ by
Ben Goldacre notes that such statements can be very misleading.
Specifically, a five-fold increase might still be negligible.

He advocates for publishing "natural frequencies" to describe risk -
meaning, "tell how many people out of 1000 will have the bad result."
In other words, tell how many people will get Afib with and without this
sort of exercise. If the numbers are low enough (even if one is five
times the other) one might reasonably judge that the increase in risk
isn't important.

--
- Frank Krygowski

[(PeteCresswell)]

Per Frank Krygowski:

>Maybe dropping dead isn't the worst part. In contrast to Grant
>Peterson's article, I was told the major risk was a stroke. While a
>stroke can kill instantaneously, it can also cause a person to live as
>an invalid, with a really lousy quality of life. :-/

The cardio guy I go to says that one's chances of stroke are reduced to
the same as the other people their age if they stay on an
anti-coagulant.

I have come across the five-fold assertion several times myself. As you
observe, the real risk depends on "Five-fold increase over *what*?"...

But, in this case, the "What" is pretty significant.... something like
six percent.... so 5x6 = 30 percent.... call it 1 in 3... double that of
Russian roulette.
--
Pete Cresswell

[jbeattie]

On Wednesday, November 16, 2016 at 12:20:48 PM UTC-8, Frank Krygowski wrote:
> On 11/16/2016 2:31 PM, jbeattie wrote:
> > On Wednesday, November 16, 2016 at 8:55:34 AM UTC-8, Frank Krygowski wrote:
> >> I just happened on this blog post by Grant Peterson of Rivendell Bikes.
> >> He's previously noted the correlation between Atrial Fibrillation and
> >> long duration, high intensity aerobic exercise. I've read at least on
> >> study that found that correlation. I've gathered that some people here
> >> have suffered Afib, as have some of my cycling friends.
> >>
> >> Since the original blog post, Grant has appended (at the top) an email
> >> from Peter White (seller of good headlights and dynamos). Peter says he
> >> found his own Afib was triggered by consumption of simple carbohydrates.
> >> He wonders if the correlation isn't Afib with exercise; instead, if
> >> it's Afib with carbo loading.
> >>
> >> http://rivbike.tumblr.com/
> >>
> >
> > http://velonews.competitor.com/cycling-extremes (mostly about other exercise induced heart conditions):
> >
> > As for electrical abnormalities, the data speaks for itself. Long-term endurance exercise results in a five-fold increase in the risk of developing AF. A review of the relevant research finds many small studies that correlate long-term sports activity with AF (incidentally, Robert Gesink of Lotto-JumboNL had surgery in May 2014 for atrial fibrillation and has returned to the sport). Though none is conclusive, collectively they indicate a pattern: “Younger patients with a lower cumulative dose of exercise have lower AF risk. Older patients with higher dosages of exercise have higher AF risk,” Mandrola said.
> >
> > “[People] criticize the studies that have been done that make this association. And they have a point: Each of the studies, individually, has flaws. They’re from one center, they include small numbers of athletes, and there’s selection bias. But taken together — there’s maybe ten to 20 single-center studies that show this association. If you put all that evidence together, there’s reason to believe that endurance athletes can develop AF.”
> >
> > Perhaps the most influential study on mechanisms of AF in athletes comes from the study of rats and the effects of endurance exercise on the atria, conducted by a group of Spanish researchers and published in the journal Circulation in 2010. Rats were run one hour per day, five days a week, for up to 16 weeks. And they paid. Compared with sedentary controls, the exercised rats displayed evidence of damage, things such as enhanced vagal tone, atrial dilation, atrial fibrosis, and vulnerability to pacing-induced AF. Detraining the rats quickly led to a reduction in the vulnerability of AF, but not structural changes. Fibrosis and left atrial dilation remained after the rats stopped exercising. Is this what is happening inside your chest when you repeatedly go out and ride your bike, before work, after work, and every weekend in the summer?
> >
> >
> > Read more at http://velonews.competitor.com/cycling-extremes#bGm3ivayVfo07BBI.99
> >
> >
> > So I drop dead. Meh. -- Jay Beattie.
>
> Maybe dropping dead isn't the worst part. In contrast to Grant
> Peterson's article, I was told the major risk was a stroke. While a
> stroke can kill instantaneously, it can also cause a person to live as
> an invalid, with a really lousy quality of life. :-/

That's true with AF, although I'm not sure what degree of fibrillation is necessary before blood flow is so poor that clots form in the atrium. I would think you would feel pretty shitty before throwing a clot -- and hopefully get treatment and get on blood thinners. Peter Cole had AF, and when he last posted, he was adjusting to life on blood thinners and, IIRC, a more sedentary life style.

>
> I won't have time to read your links for a while, but regarding "five
> fold increase in the risk of developing AF": The book _Bad Science_ by
> Ben Goldacre notes that such statements can be very misleading.
> Specifically, a five-fold increase might still be negligible.
>
> He advocates for publishing "natural frequencies" to describe risk -
> meaning, "tell how many people out of 1000 will have the bad result."
> In other words, tell how many people will get Afib with and without this
> sort of exercise. If the numbers are low enough (even if one is five
> times the other) one might reasonably judge that the increase in risk
> isn't important.
>

Another mystery to me is mortality rate -- every disease-based charity (heart, lung, cancer, alcohol etc., etc.) claims that 50% of all deaths are caused by its disease. I don't think there are enough deaths to go around for all of them.

-- Jay Beattie.

[cycl...@gmail.com]

The ONLY groups that I have ridden with that doesn't race each other all the time is racers. So I suggest that after 40 years of riding you might have a different view. When racers get new people into their groups they adjust their speed to fit the newbies. When there are hard climbs they always have someone that stays with the newbie on the climbs. When there are sharp descents they always have someone with them often leading them as a reasonable pace.

When a race is coming up and they have a TEAM entered only they are they at training speeds. Do you suppose this is because they've read training manuals and have pros ride with them that explain the proper way to train?

[cycl...@gmail.com]

Pete - did that heavy workout include the necessary cool down? Most problems with very hard rides is because the proper cool down procedures are not followed.

[cycl...@gmail.com]

Jay, this is just so much malarkey - people with long term endurance exercise almost never even know how to warm up or cool down and these are absolutely necessary for endurance riding as much as race-level power riding.

When I ride with these "endurance" groups they are on the gas out of the gate and to the car at the end of the ride. When I try to explain to them it is completely ignored so I simply don't bother with them anymore. Once in awhile I'll ride with them when I need to increase my power levels and even then I often marvel at how thoughtless they ride. The other day we dropped down a canyon that has shoulder only here and there and HEAVY traffic. These people would go so fast in the shoulder area that they were incapable of going fast across the areas with no shoulder. They would then recover enough to race across the should area again. Then when we turned up a climb I simply let them go racing each other to the top. I was probably 5 minutes behind them when I hit the top but I wasn't tired and they were still tired after than long a rest. And I didn't eat or drink anything.

After we get back I still have 6 miles to cool down after they stop at the parking lot and get in their cars. "Hey, why are you riding so slowly?" Well 5 miles at 12 mph is good for a cool down.

[Duane]

How do you know how many years I've been riding?

> When a race is coming up and they have a TEAM entered only they are they at training speeds. Do you suppose this is because they've read training manuals and have pros ride with them that explain the proper way to train?

Probably. As opposed to the ones that THINK they're racers. Those are
the ones I try to avoid as they often cause problems trying to act like
racers.

[jbeattie]

On Thursday, November 17, 2016 at 7:40:35 AM UTC-8, cycl...@gmail.com wrote:

<snip>

> Jay, this is just so much malarkey - people with long term endurance exercise almost never even know how to warm up or cool down and these are absolutely necessary for endurance riding as much as race-level power riding.

I don't think that the lack of adequate warming up or cooling down has much of an effect on the incidence of heart disease. If you warm up properly and then do hours of high output and then warm down, you've still done hours of high output. Do that enough, and it could cause SA node problems or AF or something.

> When I ride with these "endurance" groups they are on the gas out of the gate and to the car at the end of the ride. When I try to explain to them it is completely ignored so I simply don't bother with them anymore. Once in awhile I'll ride with them when I need to increase my power levels and even then I often marvel at how thoughtless they ride. The other day we dropped down a canyon that has shoulder only here and there and HEAVY traffic. These people would go so fast in the shoulder area that they were incapable of going fast across the areas with no shoulder. They would then recover enough to race across the should area again. Then when we turned up a climb I simply let them go racing each other to the top. I was probably 5 minutes behind them when I hit the top but I wasn't tired and they were still tired after than long a rest. And I didn't eat or drink anything.
>
> After we get back I still have 6 miles to cool down after they stop at the parking lot and get in their cars. "Hey, why are you riding so slowly?" Well 5 miles at 12 mph is good for a cool down.

They probably have different goals than you. FYI, warming up and cooling down are different for riders of different fitness levels. Warming up for my son is like riding tempo for me. I'd probably get dropped by a pro warming up, particular since it is popular these days to throw in brief periods of high output as part of warming up.

-- Jay Beattie.

[(PeteCresswell)]

Per cycl...@gmail.com:

>Pete - did that heavy workout include the necessary cool down?

My standard cooldown it five minutes at about half or a third of the
workout pace. Does that qualify?
--
Pete Cresswell

[(PeteCresswell)]

Per cycl...@gmail.com:

> people with long term endurance exercise almost never even know how to warm up or cool down

I never gave any thought to warming up - in fact my SOP is to get on a
machine at my chosen anaerobic pace and see how long it takes my heart
to get up to 91% of (220-Age).... as an indication of whether I'm
getting in better or worse shape... Longer=Better, Shorter=Worse.

What I am finding, however, is more like random variations - anywhere
from less than two minutes to 17-18 minutes.... I'm thinking more a
reflection on hydration, eating, sleep, and so-forth.

What say Those Who Know ?
--
Pete Cresswell

[Tim McNamara]

On Wed, 16 Nov 2016 11:55:31 -0500, Frank Krygowski
<frkr...@sbcglobal.net> wrote:
> I just happened on this blog post by Grant Peterson of Rivendell
> Bikes. He's previously noted the correlation between Atrial
> Fibrillation and long duration, high intensity aerobic exercise. I've
> read at least on study that found that correlation. I've gathered
> that some people here have suffered Afib, as have some of my cycling
> friends.

I've had heart palpatations for years, which first began happening about
20 years ago when I was doing a lot of shellacking arund my 1908 house,
in the winter lacking what might be described as adequate ventilation.
The palpitations would last 2-3 seconds. In May 2015 I had my thyroid
removed due to papillary carcinoma (thyroid cancer) and was started on
levothyroxine. They dose this aggressively to suppress thyroid
stimulating hormone (TSH), which in turn reduces the risk of any
remaining cancer cells from being stimulated into growth. But one of
the risks of this is provoking a-fib. I've had two relatively prolonged
(~12 hours) episodes now; the second of which occurred after a 65 mile
hilly (and wonderful) ride. Unfortunately the docs can't say "this
caused it" or "that caused it." There are too many confounds. The good
news is that on a diltiazem drip I went back into normal sinus rhythm
and am now also on metroprolol succinate as a rate control strategy.
They have also adjusted the levothyroxine dose down twice in hopes of
reducing the provocation to the electrical system.

> Since the original blog post, Grant has appended (at the top) an email
> from Peter White (seller of good headlights and dynamos). Peter says
> he found his own Afib was triggered by consumption of simple
> carbohydrates.

Maybe. And/or maybe something else.

> He wonders if the correlation isn't Afib with exercise; instead, if
> it's Afib with carbo loading.
>
> http://rivbike.tumblr.com/

I always take Grant's anti-carb screeds with a grain of salt or ten.
He's a strong believer in the paleo diet, which itself has little to no
credible scientific evidence to back it up compared to other diets. But
Americans in particular like extremism in the things we believe- "all or
nothing" tends to be our watchword.

[Frank Krygowski]

Actually, while I enjoy Grant's writing a lot, I take a LOT of what he
says with several grains of salt. For example, I don't intend to ever
do much pedaling using my instep to push on flat pedals.

But he can be a refreshing change to the constantly shifting
micro-adjustments to fashion. I like that he reminds us we can Just Ride.

--
- Frank Krygowski

[Frank Miles]

I'm not sure that anyone Knows (though of course some know less
than others).

Are you "random variations" ventricular or atrial-only? You probably
already know that modest ventricular variation is a GOOD thing - those
who have machine-like regularity in their beats are actually more likely
to experience serious problems.

Yes, all those other factors have an impact. If you experience significant
variations - you should see a doc! It could be an early sign of something
else going on, not necessarily of cardiovascular origin. {It was a sign
to my doc that he should investigate further, not just blow off my complaints
as someone normally aging}

[cycl...@gmail.com]

Because you write like a kid. You might be a great rider but even young riders can drop dead from over-doing it. I might be prejudiced though since I once raced motorcycles and find the way that most people ride to be both incorrect and too hard for the length of a ride.

[cycl...@gmail.com]

That's about correct in my opinion. The groups I'm riding with are riding as fast as they can and they aren't riding slower near the end to cool down but because they haven't enough energy left to ride any faster.

[Duane]

You might also be an arrogant idiot but I'm just getting that from the
way that you write.
Asshole.

[Sir Ridesalot]

On Tuesday, December 6, 2016 at 4:07:30 PM UTC-5, Duane wrote:
> On 06/12/2016 3:36 PM, cycl...@gmail.com wrote:

Snipped Troll's post

> > Because you write like a kid. You might be a great rider but even young riders can drop dead from over-doing it. I might be prejudiced though since I once raced motorcycles and find the way that most people ride to be both incorrect and too hard for the length of a ride.
>
> You might also be an arrogant idiot but I'm just getting that from the
> way that you write.
> Asshole.

This cyclingtom guy's nothing but a Troll as his posts clearly show. Best to killfile him.

These days RBT stands for Rec.Bicycles.Trolls not Tech. VBEG LOL

RBT will soon go the way of the other bicycling related newsgroups such as RBRides and RB Misc. They'll be so inhabited by the Trolls that it won't be worth it to try to sort through the Trolls posts to get to the actual bicycling related stuff that's somewhat useful.

Cheers

[Duane]

Probably good advice. I can google the fake news sites myself if I miss
the input.

[cycl...@gmail.com]

I assume that to mean that you are a young man and are angry to be caught talking about stuff you do not know a lot about.

[cycl...@gmail.com]

What is interesting is that you haven't kill-filed me. But be sure to suggest that other's do. That certainly doesn't stop me from posting. And if the dim-wits such as yourself kill-file me we will have a lot less unknowledgable jabber.

[Duane]

Your ability to misinterpret what you read is painfully obvious.

[Sir Ridesalot]

On Friday, December 9, 2016 at 2:39:26 PM UTC-5, Duane wrote:
> On 09/12/2016 12:56 PM, cycl...@gmail.com wrote:

Snipped

> > I assume that to mean that you are a young man and are angry to be caught talking about stuff you do not know a lot about.
> >
>
> Your ability to misinterpret what you read is painfully obvious.

Hey Duane. this cyclingtom Troll has trouble telling who wrote what.

mMust be bad to have such a lousy life all his enjoymemt has to come from trolling Usenet.

Like the other obnoxious Usenet Troll that frequents this newsgroup it's best to ignore them.

Cheers