Mature Question - Proceed with Caution?

[Scuby Dooby]

Interesting thread :tongeout: - an honest to goodness followup question for the good PhD though - what about other 'aerobic' activities that don't involve lifting objects, things like swimming, brisk walking, jogging? Would those be ok also?

It seems contrary to most of what I've read in the past.

 

[Dr Deco]

Dear Scuby:

Physical activity and Off Gassing

Walking, swimming, and the like are fine for off gassing. The ones that provoke the formation of micronuclei are those that require considerable physical force.

What we are alluding to here with regard to mild activity is that mild exercise is good because it can change the halftimes of the tissue. Fixed halftime compartments are what the tables are based on, but there are problems with this. Activity is based on a "so called, “one tissue” model and accords better with the data.

New Info

Some of the material that appears on the ASK DOCTOR DECO forum is somewhat at odds with information provided to SCUBA divers in the past. This arises for several reasons.

• Some of the older info is simply anecdotal. Here we might include ideas such as a previous site of injury will provoke the bends.
• Some information is incorrect according to my research and analysis, e.g., that there are fixed tissue halftimes.
• Some differences are based on US Navy studies. Here we might place the analysis that demonstrates that there are not any physical “bend/no bend” table limits;
• Sometimes it is based on changes in concepts (at least my interpretation of them) based on my studies at NASA and those of other scientific colleagues. Here we have that weight-bearing activities increase the incidence of DCS.

References

Dervay JP, Powell MR, Butler B, Fife CE. The effect of exercise and rest duration on the generation of venous gas bubbles at altitude. Aviat Space Environ Med 2002 Jan; 73(1): 22-7

Conkin J, Powell MR. Lower body adynamia as a factor to reduce the risk of hypobaric decompression sickness. Aviat Space Environ Med 2001 Mar; 72(3): 202-14

Jankowski LW, Nishi RY, Eaton DJ, Griffin AP. Exercise during decompression reduces the amount of venous gas emboli. Undersea Hyperb Med 1997 Jun; 24(2): 59-65

Loftin KC, Conkin J, Powell MR. Modeling the effects of exercise during 100% oxygen prebreathe on the risk of hypobaric decompression sickness. Aviat Space Environ Med 1997 Mar; 68(3): 199-204

Pilmanis AA, Olson RM, Fischer MD, Wiegman JF, Webb JT. Exercise-induced altitude decompression sickness. Aviat Space Environ Med 1999 Jan; 70(1): 22-9

Webb JT, Fischer MD, Heaps CL, Pilmanis AA. Exercise-enhanced preoxygenation increases protection from decompression sickness. Aviat Space Environ Med 1996 Jul; 67(7): 618-24

Dr Deco :doctor:

 

[Alban]

Dr Deco

Will high Impact excercise such as walking with a considerable load also send shock waves through the body ? I would imagine a considerable force would be sent through the heel , bones and the muscles when they are tensioned .

Excuse me for asking again about the possible effects of a bumpy ride in a R.I.B. But I was curious to know if your studies include the possible influence of external forces ?

At the risk of asking a foolish question ? During strenuous excercise the muscles will require a large amount of enegy I guess this is in the form of chemical energy from cells ? Would this leave any cavites ?

Thank you again for your time Alban

 

[raviepoo]

On no!

It sounds like carrying two heavy bags full of gear as I did last weekend, is just a bad idea after a dive tirp!

How long should one wait before engaging in strenuous activity? Is 12 hours enough? How about 24 hours?

By the way, if sex doesn't occassionaly involve heavy lifting, you're doing it wrong.

Dr Deco once bubbled...


The bad activities with respect to micronuclei generation are those that involve lifting an object. That would include climbing ladders, lifting gas cylinders, moving heavy equipment, playing volleyball, and the like.

Dr Deco : doctor:

 

[Dr Deco]

Dear Raviepoo:

Tissue Micronuclei

Micronuclei formation is a mechanical process and not a chemical one. Pressure waves are created in the fluid (just a sound waves cause pressurized and rarefied volumes). The greater the physical work, the greater will be the pressure reduction and the greater in extent this volume will be.

The easiest place to see this is in the stirring of a carbonated beverage. The mechanical work of stirring creates turbulence in the fluid, nuclei are formed, and the carbon dioxide diffuses into the nuclei and they grow. We see the drink as vigorously effervescing.

Carrying Gear

Carrying your heavy gear could result in an “undeserved hit.” That is part of the reason for the increase in DCS risk in some individuals.

One should wait at least two hours following the final dive before participating in big-time moving. This is only an estimate as true, laboratory data does not currently exist.

Dr Deco
:doctor:

 

[sactomags]

I played 9 holes after two dives one morning, and played one of my best games ever. I know I can't say that one contributed to the other, but now I am wondering if I should curtail that type of activity in the future? I did carry my bag of clubs and walked the course.

Thanks, Doc.
Margaret

 

[WreckWriter]

I wouldn't think golf would qualify as strenuous activity, even with schleping the bag.....

 

[sactomags]

But, good point.

Margaret

 

[shellbird]

Being a newbie, wasn't sure is this is advisable...

 

[Scuby Dooby]

. . . for taking the time to give such detailed info - it is appreciated!