why is exercising after diving bad?

[Bubbletrubble]

Just to reiterate...by "strenuous" or "vigorous" exercise I'm talking about sustained effort in the 80%-90% maximal heart rate zone. Athletes out there will recognize this training zone as the level of effort that pushes the anaerobic threshold. Runners hit this level of effort on a "tempo" run. A person exercising at this level is working quite hard. You aren't going to achieve that level of sustained effort by walking back to your car or schlepping around personal scuba gear after a dive.

Here are a few links to previous ScubaBoard threads that might be of interest:

• New Exercise + Diving Article
• Pre-dive/post-dive exercise and DCS
• My post in the "Why no WARM UP when diving?" thread

[Edited later: I see that Cave Diver has already listed those links. I guess I was too slow.]

 

[Mr Carcharodon]

Juardis,

I'd offer two explanations. First that exercise leads to increased blood flow to the tissues involved. That leads to faster elimination of gas which can be a good or bad thing depending exactly how fast it occurs. Certainly you can increase the pressure of dissolved nitrogen locally which can lead to bubble growth if the pressure gradients are high.

Second friction in joints and within muscles may create seed bubbles. That does happen in the lab and there is reason to think it happens in the body as well. Additional seed bubbles are additional places for supersaturated dissolved gas to go and contribute to the total bubble volume increasing DCS risk.

What to do about it? A conservative time based solution has already been offered. Other approaches are to dive shallow (say less than 30 fsw average) to keep the volume of dissolved gas down, and to long stops to help the gas in your system decompress without diffusing into bubbles.

 

[DivemasterDennis]

Since the science on this question has been presented already, let me offer a couple of other perspectives, strictly for the sake of humor and entertainment, but also providing an explanation for the suggestion of avoiding vigorous exercise for a reasonable period after diving. First, we all know that a cold beer after the last dive of the day is the best beer you will ever taste. Vigorous exercise will increase the risk of spilling your beer. Secondly, following a day of diving, having a shower, and getting dry and comfortable, it is time to gather with fellow divers and the unfortunate members of your group who did not dive, and share the stories of your dive day, whether factual, exaggerated, or completely made up. It is hard to talk or listen when engaged in rigorous exercise. Finally, if you met that special someone diving, or are on a dive trip with that special someone in your life, and meet up after clean up for that best of all beers and a little conversation, and things go well, the next move might well be a walk on the beach. A walk on the beach, not a run on the beach. Walking is fine, no where near the 80-90% of max mentioned above. Later, by the time the evening progresses to consumation (if all went well), enough time has no doubt passed that the "exercise factor" is no longer a matter of concern. And even if enough time has not yet passed according to the experts, well, some things are worth the risk! Happy diving everyone!
DivemasterDennis

 

[fjpatrum]

Also Hot soaks like hot tubbing and taking a hot shower after a dive is ill advised.

Is there any actual evidence that supports this general opinion? I know people say this and I understand that temps affect off-gassing etc. but I haven't found any empirical data to support this belief. If you have, I'd like to read it.

 

[g1138]

Also Hot soaks like hot tubbing and taking a hot shower after a dive is ill advised.

Is there any actual evidence that supports this general opinion? I know people say this and I understand that temps affect off-gassing etc. but I haven't found any empirical data to support this belief. If you have, I'd like to read it.

http://www.scubaboard.com/forums/ask-dr-decompression/364882-hot-tubs-diving-liveaboard-question.html
DAN | Medical
Hot tubs and SCUBA. DocV's Fri AM Medical Minute.+

 

[knowone]

Not sure in which direction I would walk if approached
by Private Benjamin from the other end of the beach

 

[lamont]

Who's saying 4 hours? Is that a rule of thumb in GUE/DIR circles?

No, thats mostly my own informal estimation based on reading about this issue before, and based on my own estimation of when post-dive stress has subsided and any DCS symptoms will have shown up or not by then.

 

[redacted]

Not sure in which direction I would walk if approached
by Private Benjamin from the other end of the beach

You could just sit down and off gas while you wait to see what she does. Remember, she is 65 now. (Are we going to have to have this moved to the GOD forum?)

 

[knowone]

Kate Hudson-Horn?

 

[redacted]

Her mother, Goldie Hawn, was PVT Benjamin (Private benjamin - Google Search) in 1980.