What happened? skin bends?

[gregor1234]

Re: predive exercise

I think it is a real mistake to try to translate military research in predive exercise to civilian sports diving. The military personnel used in the french study cited by CHip104 and other military studies are in excellent physical condition unlike many sport divers.

Rigorous exercise can have opposite effects on physiology depending on how well conditioned you are at the time.

Rigorous exercise in an unconditioned individual can cause subclinical tissue damage and inflammation and that, I believe, is an invitation to DCS.

On the other hand, inflammation would be minimal in a well-conditioned individual and I can imagine other ways in which pre-dive exercise could adjust a person's physiology so as to reduce the odds of DCS provided 1) that the exercise in question was within or nearly within the linits of the person's normal exercise tolerance limits and 2) the exercise caused no tissue damage. (Bowling is less exercise than running 6-8k but is more likely to cause sholder injury.) The military reseach cited above backs up the contention that exercise is preventative.

Now Spoon says he runs 6-8k so is probably in good shape but he doesn't say how often he runs it. If Spoon normally runs 6-8k/day I would suggest it has a preventative effect on DCS. But if he runs it only every other day or every third day, I would counsel him to take much more conservative dives after running on running days than on non-running days.

I would further suggest that if he runs 6-8k after a night with little sleep, that exercise is more likely to cause an inflammatory response (pro-DCS) than exercise conducted when well-rested. Furthermore, Spoon is more likly to run "sloppy' after little sleep... to run in such a manner as to put greater stress on his joints, muscles etc.

Any deco docs out there want to comment on the possible effects of inflammatory processes in DCS?

 

[CameronMartz]

Re: predive exercise
Rigorous exercise can have opposite effects on physiology depending on how well conditioned you are at the time.

Rigorous exercise in an unconditioned individual can cause subclinical tissue damage and inflammation and that, I believe, is an invitation to DCS.

There has been other research, albeit on rats for now, showing that pre-dive exercise may be protective regardless of participation in a physical training program. In fact, if you visit PubMed and do a search on "nitric oxide decompression" and the like, you will see that inflammation is not the only short-term physiological response to exercise that might have significance to risk of DCS.

Couple this with the real-world experience of divers of all levels of fitness with varying amounts of pre-dive activity, with not a single case of DCS attributed to pre-dive exercise in several years of DAN accident data, it becomes difficult to support a theory that pre-dive exercise is harmful. Dehydration, yes, and in one notable case of spinal DCS, as a result of pre-dive running. Fatigue, yes. Inflammation response to exercise, maybe, but it looks like it's offset by increased capillary response from NO, which seems to be present regardless of physical conditioning. Unfortunately, research on complement activation and DCS in general is quite equivocal, and none looks at connecting the dots from exercise to complement activation and then on to risk of DCS.

One thing to note, though, is that physical conditioning seems to improve collateral blood flow in response to blockages, again through the mechanism of NO.

Cameron

 

[Spoon]

Re: predive exercise


Now Spoon says he runs 6-8k so is probably in good shape but he doesn't say how often he runs it. If Spoon normally runs 6-8k/day I would suggest it has a preventative effect on DCS. But if he runs it only every other day or every third day, I would counsel him to take much more conservative dives after running on running days than on non-running days.

I would further suggest that if he runs 6-8k after a night with little sleep, that exercise is more likely to cause an inflammatory response (pro-DCS) than exercise conducted when well-rested. Furthermore, Spoon is more likly to run "sloppy' after little sleep... to run in such a manner as to put greater stress on his joints, muscles etc.

i run an average of 4-5k 3 times a week for 45 mins in a treadmil at a pace of 7kmh i rarely go beyond 5k and rarely jog on real pavement. say maybe once or twice a month at most. and all of my morning cardio sessions are conducted after getting an average of 7 to 8 hours of sleep in the gym treadmill. that 6-8k run was quite rare becasue i hardly go beyond 5k and it was also done on pavement which is also a rare thing. Gregor also has a point when he says i could have been sloppy, which in fact i was but not becasue i wasnt well rested but beascue of the hard pavement on my joints. i managed but i have to admit towards the end of the run my joints were sore but not painful.

 

[Spoon]

thanks a lot for your kind word guys. it just proves that dcs can hit anyone and factors and causes cannot actually be pinpointed. it also shows that no matter what your training is or how well youve planned your dive, Mother nature can always unleash something which can leave your best laid plans bunk! i have learned my lesson and will make it a point to have some sort of plan and redundancy contingency to make me and my buds more prepared for the worst case scenario. cheers.

 

[chip104]

Re: predive exercise

I think it is a real mistake to try to translate military research in predive exercise to civilian sports diving. The military personnel used in the french study cited by CHip104 and other military studies are in excellent physical condition unlike many sport divers.

Good point. That's the good thing about primary sources: it's for the reader to interpret.

Spoon, while all of us can spew off evidence, theories and opinions that will support either side, the best thing for you to do is to perform the literature search and come up with your own conclusions. I've attached an article for you bro.

Now how about we leave the poor rats alone and begin focusing on humans?

 

[PavoDive]

Spoon,
First of all, I'm glad to hear that you were cleared to dive again soon, and what happened wasn't really too serious.

I'd like to add a comment about this, though:

... it was sore and i was attributing this to sunburn because i usually sun tan during my surface intervals.

As far as I understand, sunbathing can contribute to DCS bacause of the vasodilation / vasoconstriction / vasodilation mechanism that takes place when you're exposed to the sun (hot), go diving (cold), and come again to take the sun. (the logic being that your not-very-irrigated-during dive skin will "suddenly" release a lot of N2 once your capillaries dilate with the sun's heat. --specially after deep or cold dives--)

:sunny ==> :bubbly (somebody's got to make that smily)

I know I've seen this in some book, but can't check in which one because all my books are in boxes, crossing the pacific

I couldn't find anything in DAN's site either

Perhaps somebody has some more information to share around this issue?

G.P.

 

[chip104]

btw, spoon, is it the main road you jogged that leads to AquaV (from the pier)? If so, that's pretty hardcore! good for you!