Contractions at depth

[Jussi]

Has anyone found a good way to delay contractions on constant weight dives? On deep dives I don't get any contractions during the descent, but often I'll get a contraction very soon after I start swimming up. I'm not at all sure that these are CO2 contractions, I think they could be somehow related to the change from rest to work.
The contractions wouldn't really be a problem, except that I think contractions at depth are the main reason I have had a little blood in my spit a couple of times, which is of course something I want to avoid altogether.
I have done lots of FRC-dives that I believe have been more stressful to my lungs than my deepest full-lung dives, except that I have not had contractions during these dives. There has never been any sign of blood after the FRC-dives.


At what stage during your depth dives do you get contractions? What is the best way to delay contractions on constant weight dives? The only things I can think of are hypercapnic training (only tried CO2-tables a couple of times, do they really work at delaying contractions?), a better warm-up, better relaxation and hyperventilation. The last one is not really a very good option!


I would be thankful for any input, as I don't think getting contractions at depth can be good for you. Otherwise the dives feel very good.

Jussi

[roy_nexus_6]

Jussi, This subject has been discussed before. Check out the following thread:

http://forums.deeperblue.net/showthr...9&page=1&pp=15

[Jussi]

Hi roy and thanks for the link.
That thread seems to be more about static breath holds, I don't think it applies so much to depth diving. I am specifically interested in delaying contraction during depth dives, with static and dynamic I have no problems (well, I wouldn't mind if the contractions started later in those disciplines too, but at least they are harmless in the pool

Jussi

[DeepThought]

I have wondered the same thing from the same reason (I think I got a squeeze from that once). I dove only once since then in the same condition and everything was fine. The change was doing "lung" stretches before the dive session including udayana banda, and in the first few dives (or even most of the session sometimes) to descend slowly, especially in the first 15m and start the glide phase earlier than before (=slower start).

Another thing you can try (which I didn't as I'm lazy) is to simulate your situation by doing an empty lung static and then start walking after X time, as it is similar to the problematic part of your dive profile. Maybe you could delay contractions in that way.

Anyway, whatever you will do, come back to report, I'm curious as well.