extra arm strokes on descent

[cdavis]

I started playing with extra arm strokes this summer. Normally I quit kicking very shallow and do very slow descents, to minimize effort early in the dive. Often I have nothing in my hands, so I started doing 2 or 3 arm strokes after the initial surface dive and after I quit kicking. This definitely speeded up the descent and did not seem to add much exertion to the dive. Dive time didn't change much if any, more bottom time, and I still was getting a very strong blood shift.

Anybody else try something like this?

Connor

 

[Apneaddict]

Only once, right after the duck-dive sometimes when I'm buoyant wearing a 5mm suit

 

[growingupninja]

Yes, I do a single left handed pull as I am doing my duck dive almost 100% of the time. I wear a relatively thick suit (6mm) and weight light for a spearo so I am very bouyant at surface. Since I don't use my hands for EQ I always have at least one free hand. Helps a lot. I descend relatively fast until I reach neutral (40' in CA, much deeper in FL) and then mostly coast the rest of the way, although I may continue at a fast rate due to momentum and sometimes continued light kicks.

I will try to count kicks one of these days but when I'm really in serious 'go to the bottom mode' I want to say it only takes me a split leg duck dive, arm pull, and 3-5 kicks to reach 30M. I use very stiff fins.

If I am not holding gun or lobster, I use my arms frequently on deep ascent and employ more dolphin kicks. I use my arms mostly to shift the lactic load off my legs. I try to be judicious with the arms though; while it is comfortable, I suspect I burn more core O2 with arm pulls than stereo kick near the end of a dive.

 

[cdavis]

"I suspect I burn more core O2 with arm pulls"

The real crux of the matter and what I hoped might come out of this. Are extra arm pulls in this situation more or less efficent at producing thrust than leg kicks? An additional question: Does blood shift affect the smaller muscles of the arms and chest less than the large muscles of the legs? Anybody know the answer to either of those?

I've tried arm pulls on the way up, but only when something wasn't going right. Did not seem quite right, but maybe that was just the negative situation. I will soon have a place I can train in deep water, so will try that.

On the way down, its early in the dive, so blood shift isn't well established. The same amount of muscular work in either arms or legs should have the same effect on core c02 later in the dive, unless blood shift affects the different muscles differently. Arm pulls like that felt efficient, good thrust with minimal exertion, felt more effective (I think) than kicking. I can power down easy enough with leg kicks, but that shortens my dive time and arm strokes did not seem to. Logically arm pulls early in the dive should make some difference in dive time, but I could not detect it with the amount of use I did. More testing needed.

One thing: I'm diving half lung with minimal wetsuit, so the buoyancy profile and effort profile of my dives is very different from diving full lung and/or with a thick wetsuit

 

[growingupninja]

I paid more attention yesterday to my dive and kick profiles while spearing. I can get to neutral in as little as 4 kicks but they bigger, more energy intensive kicks than I ordinarily take. I instead take more shorter amplitude kicks, and if I am serious about getting down I continue them for a while at a lower intensity even past neutral...

The reason I think arm strokes take more O2 than leg kicks towards the end is because a lot of the power is coming from muscles in the back and chest, with some involvement from the tricep, and I have never swam into a samba or even been especially hypoxic while doing pure leg DYN, but on DNF I have been pretty much there.

I don't think back/chest are as affected (maybe barely even affected) by blood shift because when I do apnea work (dry and in water) that uses my entire body, the 'no blood muscle burn' doesn't really happen there with the same intensity. Men typically have a higher distribution of fast twitch muscle in the upper body. Perhaps this has something to do with it?

 

[cdavis]

Thanks Lance, always appreciate your knowledge. I'm going to play with this some more.

 

[esom]

interesting question.
where were you on the way to (straight down?moving in the blue? oriented and swimming towards something- like fish or bottom or...?), which direction did you look to, when you felt armstrokes to make sense?

 

[cdavis]

Hi Esom,

This is during descent, on dives of 50-100 ft. Relatively straight down, but I'm a reef crawler/spearo, so I look around a lot and often don't go straight down, nor does my head stay straight. The purpose is to increase my speed of descent without burning much 02 or slowing onset of DR.

 

[esom]

Hi Esom,

This is during descent, on dives of 50-100 ft. Relatively straight down, but I'm a reef crawler/spearo, so I look around a lot and often don't go straight down, nor does my head stay straight. The purpose is to increase my speed of descent without burning much 02 or slowing onset of DR.

Cool. I think there is quite a bit to it. I will try myself the next few days (i too do it intuitively from time to time). Some obvoius enough points right away:

If the head is allowed to move and roll backwards a little, this will help the preperation and start of the armpull to be smooth. This will be a true and actual connection the other way around too - if you want to have better orientation, an armpull will let the according headmovement feel funktional and effective.

In a more complex environment than "rope in the blue" precise steering and it´s perception as such has a particular taste and meaning. Steering is updating the divers position - but as well as his feel! Understanding through action, that your steer is precise, is the only (un)reasonable reason to truly let go of preventive tension. Armpulls do make a difference in this respect.
They are connected to orientation as explained above, they are more direct and more fine in adjusting direction than finkicks, also they have a more direct feedback which means that you feel yourself steering precisely, even while exerting the armpull (e.g. it´s easy to vary the steering aspect throughout one armpull) ...this bit got a little condensed, read twice or ask please.

The mechanics of armpulls can help to transition into freefall. As spine and hips are pulled, this can serve as an information on the new configuration of tension, that will establish the transition from a kicking and its according tension (enabling kick-steering and kick-forcetransmission "headwards"), to a sink that can be executed much more gentle.

Also, varing the used movment itself is meaningful.
It can act as a symbol for the degrees of freedom and thus involvement of the diver. Like this the diver is much less a propulsion machine and more a free diver. - I believe efficient movement can only happen through high involvement of the hole diver. I´m sure armpulls can be a valuable part of a learningprocess towards good integrative technique - actually i know it for sure, as i used them in classes .


thanks for bringing it up, regards

 

[cdavis]

I had not thought of the steering aspect, but its certainly part of it. I dive mostly with a Dol-fin. I lose a bit of precision steering relative to bifins and arm strokes compensate for that loss.

I'd be interested in what you find.