From: praetzel@marconi.uwaterloo.ca (Eric Praetzel)
Subject: Re: VO2 max
Organization: University of Waterloo
Date: Tue, 1 Sep 1992 12:46:09 GMT

In article <1992Sep1.003216.6230@hpcvusn.cv.hp.com> harry@cv.hp.com (Harry Phinney) writes:
>If one is forced to go beyond AT, it matters little whether they must go
>to VO2max, or beyond.  It is (in my opinion) unclear just how much
>VO2max can be affected through training.  Most sources cite relatively
>short term studies and conclude that the average person can only
>increase their VO2max by maybe 15%.
  Interesting.  The studies which I have seen show a fast steady increase with
training for the first two months and then a quick leveling off.  This would 
seem to indicate that long term improvements are possible on some rapidly 
decreasing function but that most of your potential can be obtained within two
months.  
  However, as you have pointed out (and verified by studies) most people will
be increasing the VO2 at the AT for about 2 to 3 years.  However, several
studies have also shown that this trainability is very fitness dependant (ie
the less fit the more improvment) and very specific to certain individuals
(ie the change in fitness over several months of training is between 3% and
100% - so people do not respond well to training).

>  On the other hand, Pete Penseyres
>has been having a test done at least once a year for the last 9 or 10
>years.  Each test has shown an increase.  It is quite possible (again,
>IMO) that this is a normal outcome of a well planned and executed
>training program, but it is also possible that he's learning to take the
>test.
  Again if its due to training I would bet that it is specific to this one
individual and not representitive of the population in general.  This guy is
a genetic freek.  His base level of fitness is well in excess of mine and the
average person.

>Right, which is one of the primary reasons the VO2max is not a good
>predictor of athletic performance.  The athlete's power output at AT is
>a much better predictor, and appears to be much more trainable than
>VO2max.
  Right but I was just trying to get a measure of personal fitness that could
be used as some sort of standard.  If you are on a training program my bet is
that you could plot P@VO2 vs P@VO2max and the change in slope could be used as
an indicator that you are approaching your personal max or as Harry would say
you are approaching a point where your training regeme needs to be changed
because you are adapting to just doing one type of training.

>: If you look at your power
>: output for a given oxygen comsumption you can guage your efficiency.  That is
>: done by treating the human body as an engine, assuming that you are buring
>: basically fat and that all power generation is aerobic.
>These are a couple of pretty big assumptions.  Even at relatively low
>power levels the aerobic carbohydrate metabolism is producing
>significant power, and by the time AT is reached it is likely dominant.
>Again, by the point of VO2max, the anaerobic metabolism will be heavily
>engaged.
  I am using the same sort of comparison that you used with Pete.  I am
comparing myself to a national calibre runner who did some cycling several years
ago.  Thruout the entire VO2 curve he is putting out 30% more power than me.  It
seems a pretty intrinsic property.  Since it seems to be inherant my bet is
that it is for the most part genetically determined.  But I have seen no
studies to identify what the source of the difference is.

>: If your efficiency is low like mine (21%) you are not in danger
>: of becoming a Cat 1 or 2 or 3.
>Unless you have access to a lot more data, I don't think you can conclude
>this.
  Generally I think that it holds.  I have seen enough examples of this over
the years and you have seen enough counter examples.  Either I am untrainable
or your examples are people who take lots of time to train to their potential.

>: Perhaps the efficiency is trainable but it seems very unlikely.
>Why?  It seems that technique could affect this significantly.
  Just when I though that Keith would hop in he does not.  Studies have shown
that people are very consistant on an ergometer.  Technique variance have
not been enough of a problem to warrent any study (unlike running).  Only in
extreme cases of taking people who have never ridden bikes is there a
measurable difference in efficiency as they learn the motion.  People who
have done some basic riding don't seem to change their efficiency.  The
interesting thing is that the 30% difference between and my friend is across
the whole power range (24W to 350W).  At the end of the test I am quite 
ragged and every semblence of smooth pedaling is gone (stomp stomp stomp).
Pedalling smoothly at low power levels does not seem to offer any benefit.  But
I will grant you that a lot of things change thruout that range.  But given
that people of somewhat simular training vary by 30% in their efficiency I am
lead to believe its genetic.  The fact that a lack of clipless pedals or
real cycling shoes or different seat positions (or saddles) does not make an
appreciable change only convinces me more that the limitation is inherent in
each person.


>If you are having to eat more during rides, then I would say that your
>fat metabolism is under trained.  You are relying more heavily on the
>aerobic carbohydrate metabolism than are your friends.  Some coaches
  Yes but that is because they are running a lot lower on their curves
than I am.  Their submaximal efforts leave me past my AT at points.  I
have to make sure that I don't exceed my AT too much during longer rides.
That means that they drop me on every hill for the first 1.5 hours and
after that it takes me progressively longer to catch up; to the point of
my not seeing them for the last hour one something as short as a century.
And that is when I am doing 350 km / week to their 50, 50, 600 and not having
done my training (note individual efforts not pack work, over several different
centuries).

>(e.g.  Sleamaker, me) believe that the fat metabolism is best trained by
>long, steady paced rides at a relatively low intensity.  Some (e.g.
  I have been trying that this year and believe that it works for me.
Centuries are now easy as long as I leave my friends at home and I feel
good when I do 200 km rides until I look at my friends knocking down 
340km rides at paces fast than I can sustain for 80 km.

>Mike Walden) even believe that doing more intense training before the
>fat metabolism is properly prepared will limit further development of
>the fat metabolism (I personally doubt this).
  Me too.  The body adapts to its loads.  It does not have much of a memory.

So here we are again.  I see fantastic differences (30% in efficiency) between
people who are in a simular state of training (the the less efficient one is
better trained) and given other evidence conclude that it is basically genetic.
The trainable factors can push you higher on your power vs VO2 curve but the
curve is shifted up or down depending upon that magical efficiency.  Long term
studies have not noticed any change in the offset of the power vs VO2 curve
so I have to conclude that it is fixed for each individual.  I would love to
believe that it is trainable but being a pessimist/realist I can see no
evidence for that.  Maby I will let myself get out of shape and do a thesis
on the training changes to my metabolism over two years.
  - Eric 

From: khe@hpfcso.FC.HP.COM (Keith Erskine)
Date: Fri, 28 Aug 1992 21:17:25 GMT
Subject: Re: Ammonia Smell
Organization: Hewlett-Packard, Fort Collins, CO, USA