29 Jan 2004 09:03:32
Brian and Denise Pauley
skiing at altitude & heart rate


Hi,

Maybe you can explain this to me. I live in Wisconsin and have been xc
skate ski training for the Birkie for the past 3 months. My fitness is very
good, currently. I'm using my heart rate monitor for my training mainly to
monitor my time spent near my anaerobic threshold.

I was just out in Breckenridge and Frisco, Colorado and skied there at 10k
and 9k feet of elevation, respectively. Although, due to the altitude, I
was constantly out of breath due to lack of oxygen and totally felt spent,
my heart rate was generally well below my anaerobic threshold. I skied for
two hours one day and three the next. The way I felt, I should've been near
my threshold for quite some time, yet I only accumulated about 10 minutes
there each day.

I returned home the other day and skied for an hour and had no problem
getting my heart rate up to where it should be. Thoughts? Why would my
respiratory rate be so high in Colorado, yet not my heart rate?

Thanks,

Brian






29 Jan 2004 08:57:23
Neal Henderson
Re: skiing at altitude & heart rate

Brian,
As you increase altitude, there is a decrease in barometric pressure.
This effectively decreases the oxygen pressure, though the percentage of O2
is the same here in CO (or Mt. Everest for that matter) as it is in WI (or
any other place near/at sea level). To compensate, respiration rates
increase significantly to try to present the same amount of O2 to the lung -
and was likely increased by about 50% at the elevation you were at compared
to sea level. This is why your respiration was significantly elevated, and
will always be higher at altitude. As one acclimates, the respiratory
muscles become better trained and several physiologic adaptations occur
which enhance oxygen transport and delivery to muscles (increase hematocrit,
increase 2,3 DPG, excretion of bicarbonate, etc.). Endurance performace at
high altitudes will always be negatively affected, though, compared to sea
level and will require higher respiratory rates at the same absolute workout
intensity.

The decreased HR you observed is kind of interesting, as most
classically there is an increase in HR during exercise at an absolute
intensity in acute exposure to altitude. With a significant increase in
altitude, though, there can be a downregulation in HR...usually occuring at
more extreme elevations. There are many factors which can affect HR, so
there are other confounding variables. If you do not know the absolute
amount of work you were doing (which is pretty difficult with skiing), then
it is most likely that you were performing significantly less intense work,
but it felt much harder due to the increased respiration. Hope that helps!
Neal


--
Neal Henderson, MS CSCS
Coordinator of Sport Science
Boulder Center for Sports Medicine
phone: (303) 544-5700
web: http://www.bch.org/sportsmedicine
email: [email protected]
"Brian and Denise Pauley" <[email protected] > wrote in message
news:[email protected]
>
> Hi,
>
> Maybe you can explain this to me. I live in Wisconsin and have been xc
> skate ski training for the Birkie for the past 3 months. My fitness is
very
> good, currently. I'm using my heart rate monitor for my training mainly
to
> monitor my time spent near my anaerobic threshold.
>
> I was just out in Breckenridge and Frisco, Colorado and skied there at 10k
> and 9k feet of elevation, respectively. Although, due to the altitude, I
> was constantly out of breath due to lack of oxygen and totally felt spent,
> my heart rate was generally well below my anaerobic threshold. I skied
for
> two hours one day and three the next. The way I felt, I should've been
near
> my threshold for quite some time, yet I only accumulated about 10 minutes
> there each day.
>
> I returned home the other day and skied for an hour and had no problem
> getting my heart rate up to where it should be. Thoughts? Why would my
> respiratory rate be so high in Colorado, yet not my heart rate?
>
> Thanks,
>
> Brian
>
>
>
>




29 Jan 2004 17:17:27
Ken Roberts
Re: skiing at altitude & heart rate

I'm not a medical doctor, but I've gone from living at sea-level to
exercising at 3000 meters altitude many times.

I find that I get early symptoms of "acute mountain sickness" during your
first 2-3 days at altitude at 2500 meters / 8000 feet -- like lethargy and
nausea (other people get headaches and other symptoms). Feelings like that
prevent me from exercising as hard as I want, notably for climbing up
slopes. (I do much better just skiing down, the first couple of days). So
perhaps feelings and symptoms like that are preventing you working your
muscles hard enough to effectively use even what hemoglobin you've got, and
so you're not engaging enough muscle mass at a high enough rate to get your
heart rate up as high as you're accustomed to.

Then my doctor wrote me a prescription for acetazolamide (Diamox) -- because
I go up to altitude several times a year, so I asked him about it. Now I
start taking it a couple of days before I go up to altitude, and it helps me
a lot. I do get some "tingling" side effects, but enduring those is worth
it for me.

I've read that some of those "acute mountain sickness" symptoms are due to
lack of CO2 in the atmosphere (not the lack of oxygen, surprisingly). The
explanation I've heard is that the carbonic acid level in my blood gets
reduced, and that changes the pH of my blood -- reduces the acidity, causes
"alkalosis". Various neural/brain control mechanisms seem to interpret that
as _trouble_, and generate bad feelings (and other reactions). Like I tend
to have feelings of lethargy and nausea when I exercise hard at 2500 meters
or above the first few days. Sharon doesn't seem to get those symptoms
until more like 3000 meters / 10000 feet. After three days at that
altitude, I can exercise at much higher rates, even though that's not enough
time for my body to add very much hemoglobin capacity. But with taking
acetazolamide to help control my blood pH level, I can ramp up my exercise
level much quicker.

But this whole altitude thing is tricky, and I've read some stories recently
of much more dangerous things like HAPE and HACE hitting some skiers at 3000
meters altitude (or maybe even only 2500 meters?). So it sounds like it's
not a good idea to just rely on acetazolamide, if you don't know what else
might be happening. Best to consult with a medical doctor with current
specific knowledge about altitude-related illnesses.

Ken




29 Jan 2004 20:49:20
Re: skiing at altitude & heart rate

-----BEGIN PGP SIGNED MESSAGE-----

In article <[email protected] >,
Ken Roberts <[email protected] > wrote:
>I'm not a medical doctor, but I've gone from living at sea-level to
>exercising at 3000 meters altitude many times.
>

_ I do it every weekend I can get away and for me it's often
hit or miss. Somedays fine and somedays I suffer, I don't
keep a precise enough exercise diary to isolate any
causes. Really frustrating to put that much energy into
getting out and up there and not have the gas in the tank.


_ As far as heart rate goes, your maximum and minimum
heart rates squeeze together as you increase altitude.
Your resting hr will rise and your lacate threshold
drop. If you have the time, taking it easy the first
day or so will help a lot over a 1 week trip.

_ Booker C. Bense



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29 Jan 2004 15:54:28
Brian Pauley
Re: skiing at altitude & heart rate

Neal,

Thanks for the reply. I think you hit it on the head in the last
section of your letter. I simply think that I wasn't able to work
hard enough to get my heart rate up, or to make any lactic acid for
that matter. It always amazes me how you can feel like you are
hammering out there, yet it's not the muscles that fatigue rather it's
the cardiovascular system that puts the brakes on.

I'm assuming that this would all normalize if I'd spend more time at
altitude. I just thought I'd see if this was confusing to anyone else
as well.

Brian



"Neal Henderson" <[email protected] > wrote in message news:<[email protected].com>...
> Brian,
> As you increase altitude, there is a decrease in barometric pressure.
> This effectively decreases the oxygen pressure, though the percentage of O2
> is the same here in CO (or Mt. Everest for that matter) as it is in WI (or
> any other place near/at sea level). To compensate, respiration rates
> increase significantly to try to present the same amount of O2 to the lung -
> and was likely increased by about 50% at the elevation you were at compared
> to sea level. This is why your respiration was significantly elevated, and
> will always be higher at altitude. As one acclimates, the respiratory
> muscles become better trained and several physiologic adaptations occur
> which enhance oxygen transport and delivery to muscles (increase hematocrit,
> increase 2,3 DPG, excretion of bicarbonate, etc.). Endurance performace at
> high altitudes will always be negatively affected, though, compared to sea
> level and will require higher respiratory rates at the same absolute workout
> intensity.
>
> The decreased HR you observed is kind of interesting, as most
> classically there is an increase in HR during exercise at an absolute
> intensity in acute exposure to altitude. With a significant increase in
> altitude, though, there can be a downregulation in HR...usually occuring at
> more extreme elevations. There are many factors which can affect HR, so
> there are other confounding variables. If you do not know the absolute
> amount of work you were doing (which is pretty difficult with skiing), then
> it is most likely that you were performing significantly less intense work,
> but it felt much harder due to the increased respiration. Hope that helps!
> Neal
>
>
> --
> Neal Henderson, MS CSCS
> Coordinator of Sport Science
> Boulder Center for Sports Medicine
> phone: (303) 544-5700
> web: http://www.bch.org/sportsmedicine
> email: [email protected]
> "Brian and Denise Pauley" <[email protected]> wrote in message
> news:[email protected]
> >
> > Hi,
> >
> > Maybe you can explain this to me. I live in Wisconsin and have been xc
> > skate ski training for the Birkie for the past 3 months. My fitness is
> very
> > good, currently. I'm using my heart rate monitor for my training mainly
> to
> > monitor my time spent near my anaerobic threshold.
> >
> > I was just out in Breckenridge and Frisco, Colorado and skied there at 10k
> > and 9k feet of elevation, respectively. Although, due to the altitude, I
> > was constantly out of breath due to lack of oxygen and totally felt spent,
> > my heart rate was generally well below my anaerobic threshold. I skied
> for
> > two hours one day and three the next. The way I felt, I should've been
> near
> > my threshold for quite some time, yet I only accumulated about 10 minutes
> > there each day.
> >
> > I returned home the other day and skied for an hour and had no problem
> > getting my heart rate up to where it should be. Thoughts? Why would my
> > respiratory rate be so high in Colorado, yet not my heart rate?
> >
> > Thanks,
> >
> > Brian
> >
> >
> >
> >


29 Jan 2004 19:24:15
Serge
Re: skiing at altitude & heart rate

My case exactly, Ken.
I live near the beach and travel to ski at 7000' level.

The first day I usually experience light headache and have to breathe
hard even walking up the stairs.
Next day is a race day and I get wasted just skating uphill. It gets a
little easier on the third day, but it is too late.
I feel like the same effort takes me 10 beats per minute less on the
sea level.

Can I increase blood acidity drinking lemon juice, vitamin C and
alike?
What are side effects of this drug?


30 Jan 2004 03:47:55
Ken Roberts
Re: skiing at altitude & heart rate

Serge asked
> What are side effects of this drug?

You could check
http://high-altitude-medicine.com
which has info about Acute Mountain Sickness and acetazolamide -- and lots
of other stuff about altitude acclimatization and illnesses.

> Can I increase blood acidity drinking lemon juice . . .

I never heard of anything like that helping with altitude acclimatization
(though I have heard that drinking more plain water is a good idea). And
maybe it's not just addressing blood alkalinity that's the point -- it could
be that the specific _way_ that acetazolamide does it is important --
dealing with the CO2 issue.

Ken




03 Feb 2004 15:18:41
Re: skiing at altitude & heart rate

-----BEGIN PGP SIGNED MESSAGE-----

In article <[email protected] >,
Ken Roberts <[email protected] > wrote:
>Serge asked
>> What are side effects of this drug?
>
>You could check
>http://high-altitude-medicine.com
>which has info about Acute Mountain Sickness and acetazolamide -- and lots
>of other stuff about altitude acclimatization and illnesses.
>
>> Can I increase blood acidity drinking lemon juice . . .
>
>I never heard of anything like that helping with altitude acclimatization
>(though I have heard that drinking more plain water is a good idea). And
>maybe it's not just addressing blood alkalinity that's the point -- it could
>be that the specific _way_ that acetazolamide does it is important --
>dealing with the CO2 issue.
>

_ Apparently there is some genetic compontent to this as well,
some people respond quickly to the C02 issue and some don't.
Although it sounds stupid, sometimes it's really helpful to
just breathe extra. Take more breathes than you think you
"need".

_ As far as blasting up for 3 days, I find the second day is
always the most painful. In my experience, I find that if I
need to be "competetive" at 7K-8K, it's better to just blast
up there on the morning. This doesn't work for me for anything
higher than about 9k. The more you do this the better you
get at it. This is just me and counter's every piece of
advice I've ever seen, but it works for me.

_ Another "drug" to consider is ginko boloba, there are studies
that show that it helps with altitude adjustment. You need to
take it in suffiecent doses and over a long period for it to
be useful. I <THINK > it helps, but it's soo hard to know for
sure.

_ Booker C. Bense

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