The rat test.

One of my sources for my views on VO2 max and fitness, is the Exercise
Physiologist for the U.S. Speedskating team, Carl Foster.

In Carl's discussion of VO2 max, he places the average , untrained aerobic
system of a human at around 35 to 40 ml/kg of body weight ( the average
weight human). Elite cyclists and swimmers may be in the low 60's to 70's.
The world's best scores, by sport, belong to Nordic skiers (Cross Country
skiers), who have scored as high as 90 ml/kg.   Carl says,, in perspective,
the family Beagle ( a small dog ) has a VO2 max of around 135, without any
special training at all.  The volume or body mass of the subject being
tested is critical here, in that it has major effects on gas exchange
rates-----as Bill Mee likes to say, its about cross sectional area, and
perfusion within a huge area, compared to a small cross sectional
area----the very fat person has such poor vascularization within their much
larger mass, that it will take much longer to expose the far reaches of it
to the new gradient each deco stop represents. This, in addition to the
problem of the much larger body of the very obese, that their heart will
require much more time to circulate the entire body volume of blood through
the lungs.

The rat is a poor model for deco predictions in humans, since its tiny cross
sectional area, even in the most obese of rats, is still much smaller than
that of a human, and we would expect even the fattest rodent ( the Brett
Gilliam rodent ??) would still have a much higher VO2 max than any human
which ever existed-----with such fast gas exchange, we would not expect to
see a DCS test with lean rats and fat rats, in any way mimic human DCS
conditions. However, the "Gilliam Rodents" may set new world records on Deep
Air!!! :)
If you want to use lab animals for a trimix deco model, we will need to more
closely approximate human cross sectional area, mass, and  gas exchange
potential....
George told me that Bill Renaker looks a great deal like a large Pig---maybe
this should be the test animal :)

Regards,
Dan Volker

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