From: praetzel@marconi.uwaterloo.ca (Eric Praetzel)
Subject: Re: VO2 max (was Re: Heart Rate Survey: Results)
Organization: University of Waterloo
Date: Fri, 21 Aug 1992 21:52:09 GMT

In article <1992Aug21.121417.6321@mic.ucla.edu> scott@eggneb.astro.ucla.edu (scott evans) writes:
>>>I'm particularly curious about this because I recently had my VO2 max
>>>calculated based on 85% of my max heart rate, where max heart rate is
>>>220 - (my age).  This worked out to about 162.  I didn't believe the
>>>results, so I went and sustaind a heart rate of over 180.  What does
>>>this tell me?
  Basically the post was good but I will add a few things.  Right now I
am working on a _long_ post about VO2 max, how you can measure it and what it
means but here are some teasers.
  A VO2 max of 50 ml/kg/min is normal for 20ish males.  Pro cyclists are at
about 75.  The variance on this is very large.  There are Cat 1's with a VO2
max of 61 so having a large VO2 max does not guarantee anything.  But you do
need to have it above average to get into the game - so to speak.

>milliliters of oxygen.  The 85% means that you can work aerobically at
>85% of your maximum heart rate and still be aerobic.  This number is
  Yes and no.  When you are at your AT you will be getting about 10% (big
about) of your energy from glycogen.  The work rate that you can sustain
decreases with time.  In my case my AT is 172 and I am able to sustain 180
for almost 30 min if I don't have to last past 30 min.  However, when I am
out for > 100 mi I will keep it down in the 150's.  Your body has a fixed
amount of glycogen stored in the muscles.  When you run out you hit the wall.
The lower your pulse is the more fat (in relation to glycogen) you burn.  It
takes distance to force your body to burn fat at higher pulses.

>percentage and marathoning requires large, aerobic power outputs.  For
>the "good" cyclist (non cat I-II) this number should be more like 80%
>and maybe closer to 83% for the elite rider (yes, a few percent makes a
  Here some more explination is needed.  The number is probably best described
as a precentage of your pulse range.  For me:
  AT = 172,   Pulse max = 193,  Resting pulse = 44
Method 1:  AT / max = 89%
Method 2:  (AT - resting) / (max - resting) = 86%    [ better method ]
  I am a pretty lousy cyclist.  I can only maintain 250W of power for about
30 min.  A pro can maintain about 450W for that period (Amateur about 380W,
Junior 315W, Novice 270W).
  Yes the higher you can push it aerobically the better you will be but this
is only one part of the picture.

  Now what limits your AT?  You can improve it.  People who are bedridden can
double their AT with exercise but a person who is generally fit can only raise
it about 10 to 15%.  Studies have shown that pros may not be much more
powerfull but they run much closer to their max.  This suggests that you can
get a measure of fitness by comparing the maximal power to the AT power. Noone
has done studies on this as far as I know.
  Training will do several things:
1) Raise your AT slightly ie increase your AT pulse and hence power.
2) Increase the amount of fat you burn at lower pulse rates.  This takes more
   oxygen than burning glycogen but you have a virtual infinite supply of fat
   on your body.  --> endurance
3) Increase your peak power (ie 15 second --> sprinting).

Aside from that when you are in good shape most of your daily variations are
emotional and partially physical.  There is a large gap between pro's and
normal riders that can not be explained.  There are slight differences in
mechanical efficiency of muscles (nominal 21% +/- 6%), differences in VO2 max
(mostly meaningless since you need power at the AT).  At a race all or none
of this can matter.  If it is a mind game then it may never come to a sprint.
If its a sprint finish then it does not matter how you get to the line.  So 
you can draft all the way and cut your power output by 30%.  Your power at
the AT is a good measure of your time trailing ability.  It also happens that
it is a good measure of your racing ability in general.  If you run a bunch
of domestiques and pros thru a maximal VO2 test you can easily tell them
appart.  My one hope is that I can drag a few people out of the woodwork.  I
have not seen a good genetics vs training flame yet and I am leaning heavily
towards genetics as the limitation.  I have not seen any significent improve-
ments with training and certainly not enought to account for the large diff.
between Cat 1's and 4's.  From what I have seen and read 2 to 3 months of
good training (if you are fit to begin with) will show you what you are capable
of.  If you are not kicking butt when you go out with Cat 2's after 3 months
then you are probably Cat 3 or 4 material.
  Well thats the short version.
- Eric