Post Dive Exercise

[sschlesi]

The lugging and hauling of gear of which I spoke was immediately post dive when one has considerable dissolved tissue nitrogen. The tendency to form tissue bubbles is greatest when intense muscle activity occurs; the new bubbles will trap nitrogen and then grow to possibly cause DCS problems.

I've been wondering about post-dive exercise lately as most of my diving is from shore and climbing a steep hill after a dive is pretty common. Can you give a bit more detail on what immediately means, please. E.g. will waiting 5 minutes before climbing a big hill remove a big chunk of the risk, or does it take more like 30 minutes? Some qualification on considerable dissolved tissue nitrogen would help, e.g. does considerable mean a compartment is >80% of it's M-value? Is there any info that suggests fast/slow tissues are more/less tolerant of exercise?

[Dr Deco]

Hello sschlesi:

% Saturation

Those are good questions. I believe that strenuous activities include lifting, hauling, and climbing onto the boat with all of your gear. I believe that these activities should be avoided for at least thirty minutes, an hour if possible.

I am sure that the tissue gas loads play a role but I do not have any lab data on this. The original exercise and depress [to altitude] done at NASA by me involved individuals who were saturated. I might guess that less than 80% of the NDL might be safer with caution in activity when greater than this – but there does not exist any lab data.

Halftimes

There is experimental evidence to suggest (from me) that the tissues are the same and the halftimes are just a mathematical concept. That is a standard concept and has been acknowledged for about thirty years.


Dr Deco

[sschlesi]

Dr. Deco,

Thank you for your reply, we are all very lucky to have access to your expertise on SB.

I have one more question regarding post-dive exercise.

My understanding is that exercise generates "micro-nuclei" around which dissolved gasses may accumulate to form bubbles, I'm assuming the more micro-nuclei present the greater the odds of developing a problem.

Is there any indication more nuclei will accumulate from a period of moderate exercise (e.g. carry 20-30lbs uphill for 3-5 minutes), or from a short intense exertion (e.g. stumble while wearing 100lbs of gear and use "full" strength to prevent a fall).

Thanks.

P.S. for clarity, are micro-nuclei an known measurable entity, or a hypothetical entity? Some of what I have read leaves me with the impression that micro-nuclei are gas bubbles that are assumed to exist, but are smaller than the detection threshold of the detection methods applied to date.

[Dr Deco]

Hello sschlesi:

Exercise Intensity

From what laboratory data exist on this subject, physically intense activity the worst as far as nuclei generation is concerned. This is true if even for a short duration, i.e., a few seconds. However, some of this is relative, carrying equipment uphill for tens of minutes is stressful also.

Then again, this is also relative to not moving against gravity at all. This was a topic of my investigations while I was at NASA. Such null-gravity situations would apply only to astronauts. Yes, there is a big variation in DCS risk [with respect to problems in the lower limbs] whether you are on Earth or in space!

Micronuclei

Micronuclei are real entities found in all fluids. This is true whether we look at lava or ocean water. What is surprising is that barophysiology completely neglected what was well known in every other field. Nuclei are just being considered in the last couple of decades.

Nuclei are definitely smaller than can be detected in biological materials with current equipment. There have been attempts; some of these have involved me. All work nicely in a tank of water where the signals have no interfering factors.

Dr Deco