Mild hyperventilation or no?

[bengreen]

I have been playing with zero breathe ups, but feel like it defeats the purpose of an earlier mdr activation, as the earlier contractions make it really hard to relax thereby using more o2. So wouldn't it be safer to use mild hyperventilation (3 deep and hard breaths) to remain more relaxed, saving o2 and being more comfortable?

 

[Kars]

The 'breath-up' I think is a misleading term. What we do to prepare is, lowering our heart rate and metabolism. So I like to call it pre dive preparation.

'Purge breaths', are mend for getting rid of the stale air in the lungs. When doing more then 3 it becomes hyperventilation, some say it is a form of hyperventilation.

I think that doing hard breaths isn't conductive to keeping that relaxation of your preparation.
Try this: prepare to relax, slow down and reduce your breathing. When you feel that nice calm, focus and slowness, you exhale deeper, slow in, one time even deeper out, and then slowly full in, and slowly start your dive. The mindset during the dive is also important. I focus on relaxing after every movement, and bringing that surface relaxation down with me, by avoiding any fast or powerful movements.

I doing 1 or 2 extra deep breaths (purge breaths) before a dive is a bit of hyperventilation, but it can help to extend the comfort phase a bit so it's easier to keep going. You can build down on the amoud as your feel / progress.

 

[cdavis]

More comfortable yes, but not safer. Mild purging before a dive can be ok, but less is safer. What you don't want to do is employ a breath up technique that amounts to significant hyperventilation and cap it off with purge breaths.

Kars gives good advice. Slight addition to his "breath up" technique. Slow your breathing till you feel a very slight urge to breath. That way you avoid over breathing by accident.

This is a surprisingly complex subject. What you are looking for is as early as possible initiation of dive reflex, especially blood shift. Just using a minimal breath up, no purges, does that, but, as you discovered, isn't very comfortable. So, what you are really looking for is a long comfortable, safe dive. Getting early onset of DR, and a long comfortable dive is always a balance of blood c02 level, relaxation, lung inflation level when you dive, avoiding physical effort before DR starts to get strong, and the conditions you are diving in. That balance is unique to you, and it takes practice,both to find it and perfect it, but eventually becomes mostly automatic.

This is what I do, you will be different. Mostly forget about my breathing during first 2/3 of the surface interval. Just relax. I've trained my self to only belly breath. The last third, I focus on breathing as little and as shallow as possible, without any urge to breath. In calm conditions this gets to the point of almost non existent breathing. This is extremely relaxing, almost a "zone out" feeling. It also raises my blood co2 level. Last: 1 to 3(depends on how I feel) , 1/2 lung, diaphragm only, purge breaths. On the last one, full mildly forced exhale, inhale 1/2 a lung full and go. My descents are very slow, as effortless as possible, Diving 1/2 lung, I go negative and stop swimming very shallow. Recreational diving in good conditions in 30-100 ft, this gives me mild. fairly early contractions, a very strong blood shift and about 1:40 comfortable dive time, more if things are going well.