Dan (and list)
Your question is / was a large part of my dissertation research and the
research I did when working on my post-doc. In general, the effect of actue
exposure to altitude on distance running is VERY individualistic.
Brief points:
--Acute altitude affects highly trained distance runners much more negatively
than untrained people -- i.e. trained runners see a larger change in VO2max and
race time compared to untrained people.
--WITHIN the highly trained population, the change in race time & VO2max has a
large variation. For example, in an elite athlete cohort we studied at Indiana
in the mid-90's, the individual changes in VO2max from sea level to a simulated
altitude of 3300ft (1000m) ranged from 0 to just over 8%.
--The likely cause of this variation is related to individual differences in
pulmonary gas exchange limitations. A portion (around half) of elite endurance
athletes exhibit a phenomenon called exercise induced hypoxemia (EIH). This,
practially, means that these EIH athletes have less O2 bound to their
hemoglobin when the blood leaves the lung (i.e. less O2 loads into the blood).
--Why? Different theories abound and there are several mechanisms that likely
contribute. The primary one (arguably) appears to be what is called decreased
RBC transit time in the lung. This means that the athlete's cardiac output is
so maximized with training that the blood cells move through the lung so fast
(a short transit time) that there is not enough time for the O2 to diffuse
across the lung to bing with the hemoglobin.
--What it means for the athlete at altitude -- athletes who demonstrate EIH
will be significantly more affected (negatively) at altitude -- even very mild
ones, like 3,000ft.
--While 3,000ft is not considered high enough to limit performance in the
general population (which is true), EIH athletes in our study at 3,000ft had a
significantly larger decline in VO2max, compared to athletes who did not
demonstrate EIH. A practical example would be the results from the WC's in
Edmonton in 2001 (Edmonton, I believe, is just short of 3,000ft). The times
from that meet are (eyeballing) substantially slower than 2000 in Sydney or
2003 in Seville (despite the heat). This mile altitude issue was a significant
factor for an athlete I coached at the time, Tom Chorny. Tom won USA's in the
SC and got drilled in Edmonton. Of all the elite athletes I have ever tested
in the lab -- well over ~300, Tom was the MOST negatively affected by altitude
(in terms of decline in VO2max). We knew before he went he was going to be in
trouble.
--To answer your question of how much -- again it is individualistic. If you
had a lab, you could test for EIH and know wich athletes would likely be the
most affected. Look for SaO2 at VO2max falling in the low 90% range.
--In terms of an AVERAGE -- while I don't have the data in front of me, I
remember the average decline in VO2max at 3,300ft in our elite group as being
around 3%. As a very general rule, the change in 5k performance is roughly
half of the change in VO2max. So you could expect to see an average drop in
time of your athletes of about 1.5%. (If you want to confirm these numbers for
yourself, the study is published in Medicine and Science in Sports and
Exercise, sometime in 1997)
--For your other question -- can you do anything about it? Physiologically,
the answer is essentially no. Kind of a bummer. You would get some
mitigation of the decline if you could acclimatize to the altitude -- but that
would take at least 14 days or so. Some other things that might help --- a)
try to force a slower pace. In a more sit and kick race, the EIH athlete's
"weakness" at altitude would be exposed less. b) consider focusing on a later
meet. In the example of Tom Chorny, the NCAA's his senior year were at Boise,
which is right at 3,000ft. We knew he would be impaired there, so we focused
his peak more towards 2 weeks later at USA's in Eugene. In Boise, he did his
best to finish 8th, but in a better / deeper field finished 8th (first
collegian) at USA's in a new 7 second PR of 8:30. As a district race, is there
any way you can get through to the next round, without worrying? If so, great.
If not, maybe consider a focus on footlocker? Might not be prac!
tical though.
Best of luck,
Robert
Robert Chapman, Ph.D.
Men's Cross Country Coach
Adjunct Professor of Kinesiology
Indiana University
From: [EMAIL PROTECTED] on behalf of Dan Kaplan
Sent: Mon 7/31/2006 4:58 PM
To: t-and-f@lists.uoregon.edu
Subject: Re: t-and-f: Altitude Training Symposium
I've been meaning to ask a semi-related question. There's lots of data
out there on the performance gains of training at altitude, and the
effects of altitude on sprinting, but I can't find anything about its
effect on
