Surface Interval and exertion

[mmcdanie]

I was reading up on how nitrogen is removed from the body and found a statement that I did not expect.

"Because a diver's body is eliminating excess nitrogen for some time after a dive, heavy exercise and flying after diving are not recommended. These activities are akin to wringing the sponge on the surface. They can force nitrogen out of the system so quickly that it forms bubbles and leads to decompression sickness."

Is heavy excersie, such as lugging equipment to the next dive site on a surface interval, etc. similar to flying? I would have thought that the exertion would have helped the lungs to get rid of the gas faster?

Thanks for your comments.

 

[toddster541]

At first glance, it looks like somebody's attempt to get out of work.

But maybe something along the lines of increasing turbulence in the blood flow would make supersaturated gases bubble out? That's sort of how we used to de-gas fluids before drawing them up into high-pressure lab pumps - with some added vacuum. (And may do so again, now that the price of He is going stratospheric.)

Anyway, if it was all that dangerous for recreational divers, I would have keeled over a long time ago. (However, I can definitely report that rappelling down a cliff to get to a shore dive, then climbing back up afterwards with all of your gear, is a really dumb idea. But you can't tell that to 19 y/o's.)

 

[danvolker]

I was reading up on how nitrogen is removed from the body and found a statement that I did not expect.

"Because a diver's body is eliminating excess nitrogen for some time after a dive, heavy exercise and flying after diving are not recommended. These activities are akin to wringing the sponge on the surface. They can force nitrogen out of the system so quickly that it forms bubbles and leads to decompression sickness."

Is heavy excersie, such as lugging equipment to the next dive site on a surface interval, etc. similar to flying? I would have thought that the exertion would have helped the lungs to get rid of the gas faster?

Thanks for your comments.

Where the nitrogen saturation has been extreme, such as on a tech dive with deco stops...the norm is for the tech divers to AVOID any heavy lifting or major muscle contractions as they are getting out of the water, or for the next 30 minutes--some for much longer.....

 

[Steve_C]

As noted it depends on how long the dive was and how much nitrogen you have taken on. But even if you have to lug stuff you can be mellow about it, take a break first, walk slow, or you can push it and get the heart racing. Remember it's all layers of probabilities. Each thing you do to push the envelope removes one more layer of protection. The more layers you remove, the more a chance of a hit goes up. If not this time, then maybe the next.

 

[dumpsterDiver]

I was reading up on how nitrogen is removed from the body and found a statement that I did not expect.

"Because a diver's body is eliminating excess nitrogen for some time after a dive, heavy exercise and flying after diving are not recommended. These activities are akin to wringing the sponge on the surface. They can force nitrogen out of the system so quickly that it forms bubbles and leads to decompression sickness."

Is heavy excersie, such as lugging equipment to the next dive site on a surface interval, etc. similar to flying? I would have thought that the exertion would have helped the lungs to get rid of the gas faster?

Thanks for your comments.

and the captain said: "shut up and pull the anchor"...

 

[261311]

Honestly after a good day of diving anyways whether or not I'm within NDL (always plan to be in the near future) I avoid strenuous activities. I've been breathing dry, compressed air for an hour- I don't want to do anything but sit around and drink water. Good surface oxygen and breezes are all too welcome at that point. Does that mean I won't put away and load my gear before I lounge around? Of course, I'm a neat freak slow and steady wins the race though.

Nitrogen exits your body through your pores, not just lungs. It uses every entrance and exit any other gas would to get in and out. That's why in extreme cases the amount of excess scabs and scars on your body can delay the exit of nitrogen from your system. It's harder to dissolve through.

 

[Stealth Mode]

and the captain said: "shut up and pull the anchor"...

:laughing::laughing: too funny

 

[Phil_C]

Not sure about PADI or the other agencies but CMAS include this is advice in all their levels (one, two and three star courses). there is quite sensible rationale which relates to (if I remember right) the increased activity leads to elevated heart and circulation rates which in turn increases the risk of the bubbles in your system 'clumping' together into larger bubbles which can then cause and embolism or blockage in a capillary.

So it is not the same as flying where the risk is nitrogen coming out too fast and forming larger bubbles because of the increased pressure gradient when in an aircraft cabin which is only pressurised to 80% of surface pressure, but a risk of larger bubbles as a result of amalgamation.

A much longer/detailed discussion is here

http://www.scubaboard.com/forums/ne...g/401103-why-exercising-after-diving-bad.html

Cheers - P

 

[bygolly]

I asked a similar question some time ago in "Ask Dr. Decompression". Good replies from DocVikingo and Dr. Deco. http://www.scubaboard.com/forums/ask-dr-decompression/430376-exertions-following-diving.html

 

[fnfalman]

I'm sure that the boat crew wouldn't mind schlepping your gears to your car for a small reward.