Could air density make this much difference?

[Ken Bessler]

I just moved from 5400 ft altitude to 700 ft. I've noticed about
a 15-25% decrease in performance or an equal amount of an
increase in effort to equal my old levels. This is a measurement
of speed, distance, cadence in average and maximums spread
over a 3 week period. All other factors (my weight, % & grade
of hills, road conditions, traffic, etc.) are equal.

Could the lower, denser air be making that much difference or
should I be inspecting my Bianchi for shipping damage? I gave
it the once & twice over when it arrived and all seemed well. I've
been too busy to take it to my LBS for a tune up/inspection.

Ken

[Ken]

"Ken Bessler" > wrote in news:2rrajiF1d5cfgU1@uni-
berlin.de:
> I just moved from 5400 ft altitude to 700 ft. I've noticed about
> a 15-25% decrease in performance or an equal amount of an
> increase in effort to equal my old levels.

The thicker air at lower elevations will make a difference. Weather (heat
and humidity) will also make a difference; less so after you get used to it.

[Leo Lichtman]

"Ken" > wrote in message
...
> "Ken Bessler" > wrote in news:2rrajiF1d5cfgU1@uni-
> berlin.de:
>> I just moved from 5400 ft altitude to 700 ft. I've noticed about
>> a 15-25% decrease in performance or an equal amount of an
>> increase in effort to equal my old levels.
>
> The thicker air at lower elevations will make a difference. (clip)
^^^^^^^^^^^^^^
On the other hand, isn't it true that athletes often train at high altitude,
and gain an advantage as the body adapts to aerobic output in the thinner
air. I believe the blood gets thicker (so to speak.) Shouldn't this be
working in your favor at the new low elevation?

[Badger_South]

On Mon, 27 Sep 2004 20:25:18 +0000, Ken > wrote:

>"Ken Bessler" > wrote in news:2rrajiF1d5cfgU1@uni-
>berlin.de:
>> I just moved from 5400 ft altitude to 700 ft. I've noticed about
>> a 15-25% decrease in performance or an equal amount of an
>> increase in effort to equal my old levels.
>
>The thicker air at lower elevations will make a difference. Weather (heat
>and humidity) will also make a difference; less so after you get used to it.

Hmmm. Training at altitude causes decrease in near sea-level
performance?

I go from the Piedmont area to the Beach and seem to notice a few
percent increase in ability, though hard to discern from training
variations (good day, bad day, etc.)

Give it a week and if still having problems check the bike? <shrug>

-B

[Fritz M]

"Leo Lichtman" > wrote in message >...

> On the other hand, isn't it true that athletes often train at high altitude,
> and gain an advantage as the body adapts to aerobic output in the thinner
> air.

Living at high altitude increases the oxygen-carrying capacity of your
blood. It's like doping, but it's legal (today, anyway.)

Training at high altitude decreases the effort you can put into
training. This comes from reduced VO2 max, reduced cardiac output, and
reduced tolerance for lactic acid buildup resulting in reduced
anaerobic threshold, even after you've acclimated to the altitude.
Reduced effort means reduced training and reduced strength.

The trend today is "sleep high, train low." Many endurance athletes
sleep in hypoxic tents to induce their bodies to produce EPO.

RFM

[gds]

Badger_South > wrote in message >...
> On Mon, 27 Sep 2004 20:25:18 +0000, Ken > wrote:
>
> >"Ken Bessler" > wrote in news:2rrajiF1d5cfgU1@uni-
> >berlin.de:
> >> I just moved from 5400 ft altitude to 700 ft. I've noticed about
> >> a 15-25% decrease in performance or an equal amount of an
> >> increase in effort to equal my old levels.
> >
> >The thicker air at lower elevations will make a difference. Weather (heat
> >and humidity) will also make a difference; less so after you get used to it.
>
> Hmmm. Training at altitude causes decrease in near sea-level
> performance?
>
> I go from the Piedmont area to the Beach and seem to notice a few
> percent increase in ability, though hard to discern from training
> variations (good day, bad day, etc.)
>
> Give it a week and if still having problems check the bike? <shrug>
>
> -B


No question you should see a performance boost when losing 5000' in
altitude. Other wise Mt Everest would be easy and that bridge in
Florida would be epic.

[Blair P. Houghton]

Fritz M > wrote:
>Training at high altitude decreases the effort you can put into
>training. This comes from reduced VO2 max, reduced cardiac output, and
>reduced tolerance for lactic acid buildup resulting in reduced
>anaerobic threshold, even after you've acclimated to the altitude.
>Reduced effort means reduced training and reduced strength.

It also increases calorie expenditure under heavy exhertion.

About 22 kcal per hour per 100 feet altitude.

I honestly have no idea why, that's just what "they" say.
It could be as simple as the extra work your diaphragm
gets, but you wouldn't think a 100-foot change would make
that big a difference in that. Maybe your heart also has
to start pumping faster because even with more lung activity
you're getting less oxygen into the blood.

So his loss of performance is probably not due to energetic
limits.

Maybe he's just riding uphill both ways.

--Blair
"Happens to me sometimes."

[Blair P. Houghton]

Blair P. Houghton > wrote:
>Fritz M > wrote:
>>Training at high altitude decreases the effort you can put into
>>training. This comes from reduced VO2 max, reduced cardiac output, and
>>reduced tolerance for lactic acid buildup resulting in reduced
>>anaerobic threshold, even after you've acclimated to the altitude.
>>Reduced effort means reduced training and reduced strength.
>
>It also increases calorie expenditure under heavy exhertion.

exertion

--Blair
"Maybe my head needs a new chain..."

[BringYouToLife]

You sound like you might just be a pussy, Ken. Try pedaling harder.

[BringYouToLife]

Ken, sometimes you might have a cold, you can have a bug or a cold for
a week or two, you may feel ok, but will ruin your athletic
performance. Try taking a couple days off.

[Ken Bessler]

"BringYouToLife" > wrote in message
m...
> Ken, sometimes you might have a cold, you can have a bug or a cold for
> a week or two, you may feel ok, but will ruin your athletic
> performance. Try taking a couple days off.

That's interesting as I had a bad cold for the week before I
moved.

Ken

[Brent Hugh]

"Ken Bessler" > wrote in message >...
> I just moved from 5400 ft altitude to 700 ft. I've noticed about
> a 15-25% decrease in performance or an equal amount of an
> increase in effort to equal my old levels. This is a measurement
> of speed, distance, cadence in average and maximums spread
> over a 3 week period. All other factors (my weight, % & grade
> of hills, road conditions, traffic, etc.) are equal.
>
> Could the lower, denser air be making that much difference or
> should I be inspecting my Bianchi for shipping damage? I gave
> it the once & twice over when it arrived and all seemed well. I've
> been too busy to take it to my LBS for a tune up/inspection.

Air resistance alone will slow you down about 1 MPH, according to the
Bicycle speed & power calculator:

http://www.kreuzotter.de/english/espeed.htm

(1MPh difference is assuming 160 watts power output on the flat as
well as some other things about the bike, tires, weight, etc.)

--Brent
bhugh[at]mwsc.edu
www.MoBikeFed.org

[Blair P. Houghton]

Brent Hugh > wrote:
>"Ken Bessler" > wrote in message
>...
>> I just moved from 5400 ft altitude to 700 ft. I've noticed about
>> a 15-25% decrease in performance or an equal amount of an
>> increase in effort to equal my old levels. This is a measurement
>> of speed, distance, cadence in average and maximums spread
>> over a 3 week period. All other factors (my weight, % & grade
>> of hills, road conditions, traffic, etc.) are equal.
>>
>> Could the lower, denser air be making that much difference or
>> should I be inspecting my Bianchi for shipping damage? I gave
>> it the once & twice over when it arrived and all seemed well. I've
>> been too busy to take it to my LBS for a tune up/inspection.
>
>Air resistance alone will slow you down about 1 MPH, according to the
>Bicycle speed & power calculator:
>
>http://www.kreuzotter.de/english/espeed.htm
>
>(1MPh difference is assuming 160 watts power output on the flat as
>well as some other things about the bike, tires, weight, etc.)

Nifty toy. Virtually nails the speed difference I see
when going from the top of the bars to the drops at the
same power output. (It ought to feed this difference back
out through the cadence variable also but for some reason
it doesn't).

But I don't think it takes into account the altitude when
calculating the calorie output. As I've posted before,
a reputable source (which of course I do not have the
bibliographic data for at the moment) indicates that every
100 feet in altitude is worth an extra 22 kcal per hour
of aerobic exercise (regardless of weight and the exact
level of effort).

--Blair
"YMMV"

[velomanct]

Brent Hugh Wrote:
> "Ken Bessler" > wrote in message
> >...
> > I just moved from 5400 ft altitude to 700 ft. I've noticed about
> > a 15-25% decrease in performance or an equal amount of an
> > increase in effort to equal my old levels. This is a measurement
> > of speed, distance, cadence in average and maximums spread
> > over a 3 week period. All other factors (my weight, % & grade
> > of hills, road conditions, traffic, etc.) are equal.
> >
> > Could the lower, denser air be making that much difference or
> > should I be inspecting my Bianchi for shipping damage? I gave
> > it the once & twice over when it arrived and all seemed well. I've
> > been too busy to take it to my LBS for a tune up/inspection.
>
> Air resistance alone will slow you down about 1 MPH, according to the
> Bicycle speed & power calculator:
>
> http://www.kreuzotter.de/english/espeed.htm
>
> (1MPh difference is assuming 160 watts power output on the flat as
> well as some other things about the bike, tires, weight, etc.)
>
> --Brent
> bhugh[at]mwsc.edu
> www.MoBikeFed.org
at such a lower power output, speed will not be affected as much by
the difference in air resistence. 1mph seems right, at 15-20mph.

the original poster should definitely see an increase in power output
at the same effort level. speed will be about the same, because of the
greater air resistence at a given speed. but he should be producing
more power because of the greater oxygen supply.
if he doesn't have a powermeter, then a good way to test this is to
climb some hills. he should feel like he is climbing hills faster at
sea level.


--
velomanct