exercise?

[letoktok]

I read in a post that you should not exercise, no streanuous anyway. I am a pretty outdoors person, i rock climb, bike ride(road) and do motocross. So if i am diving a lot sould i restrain from thoses activities?

 

[SDAnderson]

I'm not a Doc, but I think that the information you have relates to pre- and post-dive exercise. It seems that a little bit of exercise helps your body to decompress faster but too much/hard seems to be dangerous. The general proviso is no hard exercise for at least several hours before or after a dive. Likewise, no hot showers for awhile after a dive.

Search this board, the topic has been discussed before.

Steven

 

[Rick Inman]

I read in a post that you should not exercise, no streanuous anyway. I am a pretty outdoors person, i rock climb, bike ride(road) and do motocross. So if i am diving a lot sould i restrain from thoses activities?

The answer I got:

Dear rick:

This is a frequently asked question and the answer has not been studied specifically for scuba divers. Based on a study referenced below (and mentioned by DAN), the half-life of gas micronuclei is one hour on the average. Some subjects had bubbles whose half-life was as much as two hours. If one waits at least six hours between exercise and diving, I would guess that this would be sufficient.

Strenuous exercise immediately following a dive is potentially harmful. Divers are always in search of the perfect decompression meter or table and such does not exist. Some individuals, if they exercise hard enough will get the “bends” as a recreational diver if they perform strenuous activities with their muscles. However the avoidance of heavy lifting, climbing ladders with full gear, etc, will help reduce this DCS risk considerably.

The duration after diving for exercise is a function of the residual gas in the body. I would suggest waiting six 60-minute halftimes, six hours. This would assure that gas tensions are low enough so that nuclei formation will not be followed by nuclei enlargement.

Dr Deco

References


The effect of exercise and rest duration on the generation of venous gas bubbles at altitude.

Dervay JP, Powell MR, Butler B, Fife CE. Aviat Space Environ Med. 2002 Jan;73(1):22-7.

BACKGROUND: Decompression, as occurs with aviators and astronauts undergoing high altitude operations or with deep-sea divers returning to surface, can cause gas bubbles to form within the organism. Pressure changes to evoke bubble formation in vivo during depressurization are several orders of magnitude less than those required for gas phase formation in vitro in quiescent liquids. Preformed micronuclei acting as "seeds" have been proposed, dating back to the 1940's. These tissue gas micronuclei have been attributed to a minute gas phase located in hydrophobic cavities, surfactant-stabilized microbubbles, or arising from musculoskeletal activity. The lifetimes of these micronuclei have been presumed to be from a few minutes to several weeks.

HYPOTHESIS: The greatest incidence of venous gas emboli (VGE) will be detected by precordial Doppler ultrasound with depressurization immediately following lower extremity exercise, with progressively reduced levels of VGE observed as the interval from exercise to depressurization lengthens.

METHODS: In a blinded cross-over design, 20 individuals (15 men, 5 women) at sea level exercised by performing knee-bend squats (150 knee flexes over 10 min, 235-kcal x h(-1)) either at the beginning, middle, or end of a 2-h chair-rest period without an oxygen prebreathe. Seated subjects were then depressurized to 6.2 psia (6,706 m or 22,000 ft altitude equivalent) for 120 min with no exercise performed at altitude.

RESULTS: Of the 20 subjects with VGE in the pulmonary artery, 10 demonstrated a greater incidence of bubbles with exercise performed just prior to depressurization, compared with decreasing bubble grades and incidence as the interval of rest increased prior to depressurization. No decompression illness was reported.

CONCLUSIONS: There is a significant increase in decompression-induced bubble formation at 6.2 psia when lower extremity exercise is performed just prior to depressurization as compared with longer rest intervals. Analysis indicated that micronuclei half-life is on the order of an hour under these hypobaric conditions.

 

[letoktok]

Thanks, good stuff, guess i will keep my eye out on more textes, but will take my time after dives...

 

[Dr Deco]

Hello Scuba Board Readers:

NDLs

While we normally do not think of this, NDLs are a function of many factors. Gas loading is the most obvious, but they are also a function of exercise level (including whether or not you are walking), and other factors such as hydration level and personal fitness.

Heavy exercise before and after a dive will affect the out come. Dive tables were not developed with surface exercise in mind.

Dr Deco :doctor:

 

[letoktok]

But i was thinking of buying a "scuba kayak", would that even be considered a no no?

 

[Dr Deco]

Hello Letoktok:

There is not anything wrong, vis-à-vis decompression, with mild activity, and this would include the kayak. The assumption is that you are performing moderate exercise. Paddling around in the water helps the heart rate, and promotes tissue blood flow by means of the muscle pump.

Dr Deco :doctor: