>Dan
>
>What do you consider to be a good or a minimum VO2 max level for
>Technical/cave diving.
>
>Thanks
>
>Marty Hopwood
>105 Tullamore Road
>Garden City, NY 11530
>914-337-8545 work
>516-741-5085 home
>mmh441367@ms*.co*


An  "average person" would have VO2max values in the vicinity of 35 to 45 ml
per kilo of body weight,----An elite athlete may reach 90 ml/kg of body
weight.  I would like to test the WKPP teams for the average VO2 max values
of their team members, and use this as a target for tech or cave diving,
with a minimum standard somewhere around the 45 to 50 ml/kg of body weight
level---any lower would imply more physical training is necessary before the
diver gets passed in this portion of the medical screening.

One would expect a huge fat slob without aerobic training to pull VO2 max
values as low as 10 or 15 ml/kg, and perhaps even considerably worse in the
case of smokers.
The test on the ergometer that will arrive at the VO2 max scores, will also
provide us with the power output generated by each individual. We should be
able to create a formula which will predict how fast a heavily overweight
diver could swim before attaining dangerously high CO2 levels ( indicating
if they can really swim in any meaningful way at all) , , and this should
also give us the info we need to create a formula to estimate how much
weight a horribly overweight diver could lift off the bottom at
depth---i.e., as when  Andre Smith, burdened by 4 steel tanks with very
negative buoyancy, was faced with having to generate a prolonged power out
put to swim himself up off of the bottom, to the point at which the wet suit
would add buoyancy to assist him---this model could predict the max weight
he could lift through swimming, to make up for whatever lift his wings
system could not deliver.
Regards,
Dan Volker

>-----Original Message-----
>From: Dan Volker <dlv@ga*.ne*>
>To: Bill Bowden <BBOWDEN@co*.vo*.fl*.us*>
>Cc: roger steele <rogersteele@ho*.co*>; RMC <brownies@ne*.ne*>;
>GIRVINE@bl*.ne* <GIRVINE@bl*.ne*>; Errol Kalayci
><errol@ga*.ne*>; Bill Mee <wwm@sa*.ne*>; 'cavers'
<cavers@ww*.ge*.co*>;
>techdiver <techdiver@aquanaut.com>
>Date: Tuesday, February 24, 1998 12:19 PM
>Subject: Re: Divers Supply, IANTD, Tom Mount and tragic
>technicaldiving -Reply
>
>
>>
>>From: Bill Bowden <BBOWDEN@co*.vo*.fl*.us*>
>>To: dlv@ga*.ne* <dlv@ga*.ne*>
>>Date: Tuesday, February 24, 1998 11:20 AM
>>
>>
>>
>>
>>>Dan,
>>>
>>>I appreciate you and others keeping this information coming.  Would you
>>>post the medical requirments for deep trimix diving?  I'm especially
>>>interested in any testing (esp. pulmonary function) that should be done
>>>either before diving, or on an annual basis.  Could you please explain
the
>>>relationship of weight to gas transfer?  Thanks.
>>>
>>>Bill
>>
>>From a physiological standpoint, there are enormous differences
>>which would occur between an overweight , sedentary diver, and a
worldclass
>>cross country skier ( elite level Cross country skiers are known for
having
>>the highest VO2 max levels among sports requiring aerobic power). While
the
>>differences could be dramatic here, in the real world, there are people
who
>>dive, who represent shifts from the average model, in each direction. As a
>>diver gets closer to either extreme, the relevance of the issue becomes
>much
>>greater.
>>In this example, our Olympic Cross county skier / diver, has a HUGE VO2
>Max.
>>This means that he can process  over twice as much oxygen per kilo of
>>bodyweight, than the "average diver", which the tables are based on.  What
>>this also means, is that all gas exchanges can  be drastically increased
in
>>this athlete's body, if his heart and breathing rate get elevated by
>>exertion. If he is exerting, in addition to much more oxygen uptake....CO2
>>will exit much faster ( this is good); Nitrogen will enter much faster
>>nitrogen enters the blood by gradient, at the alveoli....if this gradient
>>exposes twice as much blood , because this man can move twice as much
blood
>>through his body and lungs as can Joe Public , more nitrogen will be
>>ingassed---a lot more. This can be bad---BUT, the skier  can also offgass
>>much faster at a deco stop ...so if our skier spends enough time at a deco
>>stop, he can very efficiently rid his body of nitrogen gradient.
>>
>>Before we get to the overweight diver, there is still more to the skier's
>>issues----he CAN do an easy relaxed dive,  or maybe being towed by a
>>scooter, in which case his heart rate drops to about 45 beats per minute.
>>His breathing rate drops to about half of the breathing rate of the
>"average
>>diver", maybe even one fourth of it. While he is still exposing himself to
>>nitrogen gradient at depth, much less blood is being pumped now ( volume
of
>>blood pumped is based on the number of beats per minute of the heart---
and
>>on how much blood the heart pumps per beat. Some athletes pump large
>amounts
>>per beat, others pump more normal amounts per beat, but their hearts can
>>pump at rates far higher than normal people---some can hit 240 beats per
>>minute.) Bottom line here is that this athlete is able to move
>>considerably less blood through his body and lungs, if he relaxes and
slows
>>his heart,, due to his ability to efficiently power his body with a very
>low
>>heart rate and low volume of blood moved. So he is capable of
>>ingassing MUCH LESS nitrogen than the average diver, if he takes it very
>>easy on the dive ( as would say, a macro photographer, or a cave diver
>being
>>towed by a scooter).
>>Now we are looking at a person who has a huge range of decompression
>>obligation, which is based heavily on his own exertion rate, and his
>fitness
>>level. He might need quite less than the PADI tables may suggest on a
macro
>>photo dive, or he might need a great deal more deco than the tables
>suggest,
>>if he does a fast spearfishing dive, or if he goes crazy during lobster
>>mini-season.
>>
>>Now the heavy guy. Unlike some heavy guys who swim, cycle, or at least try
>>to train themselves aerobically, this guy works 10 hours per day, and has
>no
>>interest in aerobics. But he likes to dive.
>>Since VO2 max will be his ability to process oxygen, per kilo of body
>>weight, he has TWO strikes against him---One--his high body weight would
>>dilute any chance of having a high score if he trained aerobically , and
>>TWO, since he does NO aerobics, he has no peripheral adaptation, no
>>cardiovascular efficiency, and he starts off with a very low value for the
>>amount of oxygen he can take in---when this gets divided by his large body
>>weight, you can see how poor his gas exchange is going to be. This guy
>would
>>breath heavy doing a fast walk to the end of his driveway.  However, for
60
>>foot dives, he will ingass slower than the PADI tables would suggest.  But
>>he will also out-gass slower, meaning if his safety or deco stop is not
>>longer than the normal 3 minute stop most "average" divers perform, he
will
>>not be able to rid himself of as much nitrogen as the average divers will.
>>And his high fat level will retain nitrogen longer than the average model
>>will predict for , since this is such a large area, with poor
>>vascularization--poor bloodflow. If he does multiple dives like this, he
>>will get into greater and greater trouble, as the table fails worse and
>>worse in representing his true off-gassing rate. Or , if the heavily
>>overweight diver goes to extreme duration on a deep dive, the deco model
>>will not protect him from his much slower offgassing performance.
>>
>>The ultra fit diver, will have the tremendous safety advantage of keeping
>>their heart rate at a very low rate during the working portion of their
>>dive, through use of a scooter, or by attention to slow , efficient
>>movemement.  Additional advantage to these elite athletes will accrue
>>through knowledge of deep breathing techniques, which anyone on this list
>>can obtain by taking a good Yoga course. This will create better gas
>>exchange, and lower CO2 levels before they can reach levels which could
>>become uncomfortable. On the deco portion of the dive, heart rate can be
>>accelerated, and blood flow can be doubled, even tripled  easily. This
will
>>provide them with a tremendous advantage in off-gassing, over the
"average"
>>or "gas exchange challenged"  divers.   This is just one of the reasons
>that
>>a population of divers like the WKPP team, each with  the VO2 max levels
of
>>a competitive athlete, will have no incidence of DCS, in a run of 1000
deep
>>penetration dives, while another population of fat, aerobically unfit
>divers
>>will have a HIGH rate of DCS incidents, and or other more serious
>>complications.
>>
>>Since I and others have
>>condemned various individuals in the TDI and IANTD camps, for smoking
>>cigarettes and or pot, carrying huge ( I MEAN HUGE!!)  slabs of adipose
>>tissue around proudly,  for their lack of aerobic conditioning, and for
>>their failure to admit that  many of their top people are dangerously
unfit
>>for technical diving, and potentially so far off the recreational tables
by
>>their poor fitness, that they should not even dive normal recreational
>>profiles----It is with this in mind that this post runs long, but also
>>covers the physiological basis for many who we have condemned.
>>
>>Testing for VO2 Max, can easily be done on a bicycle ergometer. Many gyms
>>with good personal trainiers can do this for you quite inexpensively. a
>>better measure still, would be to set up an ergometer in a chamber,
>simulate
>>250 or 300 feet, and see the DRAMATIC gas exchange   differences which
will
>>occur between the 100 pound overweight diver, and the elite level athletic
>>diver. Underwater, this would be the difference between a fit diver being
>>slightly uncomfortable, having to pull themself upcurrent for half a
>minute,
>>and a dangerously overweight diver seeing a cool looking shipwreck, and
the
>>increased heart rate alone,creating so much extra CO2 , that they get clos
e
>>to toxic levels---even without trying to exert . The sooner someone starts
>>testing this as mandatory medical screening,  the sooner we will save the
>>lives of divers who have been IANTD or TDI certified to do something they
>>are ABSOLUTELY UNFIT for, and which puts them at EXTREME RISK.
>>
>>Regards,
>>Dan Volker
>>
>>
>>
>
>
>
>


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