Oregon Pool Training Weekend Results

[wes]

We had a great first ever Oregon Pool training weekend with three training in our local pool. Here are some results that one freediver, John McGinty agreed to let me share with you and that may help others understand what we are doing.

Freediver: John McGinity
Age 56 years
General Fitness Level - Excellent
Resting Heart Rate: 60 BPM
Previous Freediving Training: PFI Intermediate Course
Freediving Experience: Average amount of non-competitive freediving/spearing, no competitive freediving.


Note that the minimum SaO2 (saturated Oxygen) is measured at fingertip with Nonin Onyx fingertip pulse oxymeter after the subject has surfaced. There is typically a 10 to 30 second delay between resumption of breathing and the minimum registered SaO2 reading. I have done hundreds of these measurements and have found them to be very informative and reliable if care is taken to relax the arm and remove any pressure on the arm (like from pushing down on the pool edge).

We trained the first night with some 25m dynamics with fins on 60 second intervals mainly to improve technique and get used to the interval training technique. This is where one leaves every say 60 seconds no matter how long the lap took, so it may be 30 seconds of swimming and 30 sec rest or 20 sec swim and 40 sec rest. It is easy to do if there is a clock as you merely leave every time the second hand comes to point up.

So after 30 minutes of technique training and after a (short) 2 min break to re-oxygenate John did a:

"No warm up" 1x25m (25m total) with hold to 60 seconds total time. This means that John swam 25m and then held his breath as he rested at the end of the pool for about 30 more seconds for a total of 60 second. This simulated a 50m swim which John was sure he could do though didn't feel that comfortable just doing right then.
John had minimum 77% SaO2

77% SaO2 reading means that a bit over 1/2 of the air has been used up. The reading will go down to around 34% before blackout and of course starts at 100% To figure the exact amount of "air" left from the reading isn't directly possible as at first oxygen is used from the lungs so the SaO2 won't go down at all for 30 seconds say, and then later after 60 seconds the dive response sets in so the oxygen is used more efficiently slowing the drop in SaO2.

So John knew that he had lots of air left after 25m + 30 sec, (simulated 50m) and knew from his SaO2 reading that what he was feeling was mainly Co2 buildup and dive response. It was important for John to realize that what he was feeling was not lack of oxygen for any body function though rather a pretty high build of of Co2 as we hadn't done much/any purge breathing and his bodies dive response.

The next day we did the following and to note John was wearing a 7mm suit top with hood and using cressi Gara plastic bi-fins.

First thing John did 2x25m (total 50m) with no warm-up as follows:
First turn at 29 seconds
End at 56 seconds
Ending min SaO2 80%

We did this on John's first dynamic of the day as a baseline so he could compare on other days for his first try. This 80% SaO2 reading also makes sense to be higher than the night before (77% SaO2). This is because John had excercised alot more before that and had a short 2 min warm up which we did to save time and also he was a bit cold (light shirvering) the night before.

Next we tried a 2x25m on 2 min interval and John stopped at 25m on his second set as it seemed to intense for him so he rested and we decided to try again with 4 trials of 2x25m on 2:30 intervals and here are results:

Trial 1
Start at 0:00 and do 2x25m (50m total)
Min SaO2 after trial #1 of 79%
(note the 2x25m wasn't times though took about 60 sec so John had 90 sec to recover for total interval of 2:30)

Trial 2
Start at 2:30 and do 2x25m (50m total)
Min SaO2 after trial #2 of 83%

Trial 3
Start at 5:00 and do 2x25m (50m total)
Min SaO2 after trial #2 of 84%

Trial 4
Start at 7:30 and do 2x25m (50m total)
Min SaO2 after trial #2 of 85%

This was very very intense for John and he did great to do all 4 trials back to back like this. John did say that his first trial seemed easy and his second harder and third hardest and fourth a bit easier. Note that his first trial that had the lowest SaO2 at end seemed the easiest, this is because John was experiencing less CO2 build up and less dive response. The fact that trial 3 and 4 have higher SaO2 results seems to be from more dive response as for sure the body is more tired and not fully recovered inbetween trials like this. I have done lots of similar trials and the third trial for me always seems the hardest yet will have the highest SaO2 reading confirming the dive response theory. I think after 4 or 5 trials the body does get more and more tired so slowly erodes the oxygen remaining.and I have witnessed this going out to 10 or more similar trials.

So in doing this John got to feel his dive response a lot, and hopefully be more comfortable with it kicking in. John also got used to the benefits of more efficient breathing and "dumping" of CO2 between trials. For sure you could call the breathing in between trials hyper-ventilating though it is not really artificially lowering the CO2 level, rather it is getting rid of excess CO2 in between trials. John also got to see that with good technique and dive response he could do 2x25m and still be at 85% SaO2 which is quite a bit more than 1/2 the total air, maybe 60% of total air left.

So after some other people went and John had some time to rest we did a personal best attempt of 75m for John.

John succeeded in dong 75m so new personal best (his previous was 50 I think). Unfortunately I cannot find John's SaO2 reading after this trial so maybe John if you remember can post. I think it was around 60%-65%. This would make sense from above and correspond to a max potential for John to do 100m and be around 35-40% so close to black out. John agreed with this stating he felt "good" coming up at 75m and didn't feel he had pushed to 100% (and this was not the point).

So the point of sharing the above is to show how useful and fun it can be to use a SaO2 meter while training. The Nonin Onyx fingertip unit is small runs on batteries and costs about $300 and is not waterproof so some care needs to be taken there though it has worked great for me for over 2 years.

Thanks for taking the time to read this long post and hopefully it was worth it. I will try to answer any questions about the above and John posts to DB too so if you have some for John he will probably chime in.

Cheers Wes Lapp

 

[Mullins]

Interesting read Wes, I'd like to do some testing like this at some stage too.

I think the increasing O2 sat over consecutive swims might be due to lowered vasoconstriction. I.e. you get quite a lot of vasoconstriction on the first swim which gives you a big differential between O2% at the core and O2% at the fingertip, hence the low reading there. After a couple of swims the effect lessens, there is greater bloodflow to the periphery and so the fingertip reading is higher. I know this is at odds with the traditional view of the dive response improving over multiple dives, however many now disagree with that traditional view. I know that my performance (real performance, i.e. time/distance to BO) decreases dramatically after the first dive. Comfort increases, but comfort does not relate to performance.

The higher reading when using a thick suit makes sense in a similar way: warmth = vasodilation. Note also that when John simulated a 25m length by doing a 30 second static (which doesn't quite match up, but never mind) for the first test, that time spent motionless would have given him great vasoconstriction which would lower the fingertip reading. The cold would have made the effect more pronounced.

Umm, BO at 35% sounds rather optimistic. Isn't it typically around the 50% mark?

 

[wes]

Dave,

Great hearing from you and thanks for your excellent points and questions. I will start with sharing some relevant data I have then go into some of my theories in more depth.

First it is important to understand how the fingertip data collection protocol I use works. Essentially I don't pay any attention to the reading until after I have resumed breathing and then watch is at it drops, usually quite suddenly in 10 to 20 seconds to a minimum after which it spikes back up to 98 or 99% within 5 to 10 seconds. The only thing I really look at is the minimum number which I record.

A few I have noticed using this technique is that the more severe the Apnea is the longer it will take the SAO2 reading to reach its minimum. Also because the meter is not waterproof it is necessary to dry the subjects finger with a towel then apply the meter after they have surfaced so this takes some time and then the meter has to callibrate then give a reading so usually it won't work on readings under 90% as they come back up to normal after breathing too quickly, maybe only 5 to 10 seconds after breathing and this isn't enough time to get the reading so it will just read 98% when you finally get it on and all so you have missed the minimum.

Conversely when the apnea is quite intense it is very easy to get a good reading as the minimum will take 20 seconds or more to appear after breathing so you dry the finger, put the meter on and the reading is still diving and it will go on for 10 more seconds kind of like 80%, 75%, 73%, 71%, 70%, 69%, 71%, 78%, 89%, 98%. When it does this its very easy to say, for sure the minimum reading was 69% so there is a relationship with more intense Apnea and lower reading and longer time to indicate minimum reading after resumption of breathing.

Also on the minimum attainable reading I have lots of data on that.

-From AIDA comp, after 75m DNF I had reading of 82%

-From AIDA comp, after 125m DNF I had reading of 49%
(This reading from the video I checked and the minimum came about 21 seconds after I surfaced and resumed breathing._

-From AIDA comp, after 6:41 static I had reading of 38%
(Note on this one I completed SP OK though let my airway surface very briefly about 30 seconds prior to end of hold so was technical SP failure, on the video you can see I am quite hypoxic with one pretty severe head bob on surfacing).

-On the couch at home after static tables I have had 34% as lowest and I think you could not go this low at AIDA comp as on the couch I don't move at all and during AIDA comp static even you move some when surfacing etc.

So on accuracy the Nonin Onyx has lots of test data showing it is very very accurate and most accurate of portable SAO2 meters, within 1-2% error. This of course is for the blood at the fingertip which is different then the blood in the brain or whatever relating to how much Oxygen reserve you have.

I would say on correlating the min fingertip SAO2 with oxygen reserve after Apnea in general it has been very very aligned with my performance indicators such as sambas seen in video and loss of bladder control at the end of statics, (this happens for a few second or two whenever I go under about 40% SAO2) I don't know of any study on this though it would be very interesting and not to hard to do I don't think to correlate min fingertip SAO2 with actual blood SAO2 near the brain or whatever.

As to the meaning of the interval SAO2 readings I have seen many times the highest reading be the third try in an interval so for sure its some repeatable thing, not a fluke. I have also noticed that the perceived ease of an interval, especially for the first 4 starting out is exact opposite of the SAO2 reading. The interval that feels worst will have highest SAO2 and the interval the feels best, usually the first interval and then maybe again after 6-8 intervals will be the lowest SAO2 reading.

So everything above this is supposed to be (objective) data and below my theories:

I agree with theory that first try no warm up is best for dynamic and I use this myself for comps. In the interval work we are not going for max attempt. My max DNF is 125m and I typically do intervals of 50m every 90 seconds for training so interval is about 1/2 or less of max attempt. At the same time I do not think more or less dive response (vascoconstrction) alters the reading except that more dive response delays the reading longer after resumption of breathing. I think to explain how the third interval typically has highest O2 is that the dive response is just starting in the first interval and the body has less baseline O2 load as its starting from rest so the dive response is just starting to happen after the first interval and 50m distance (maybe 55 sec of time) and it gets interrupted with 30 second of recovery breathing. On the second interval the dive response happens faster, the initial heart rate is more, there is more latent CO2 so dive response is more quick and this saves core blood O2 levles. On the third interval CO2 is even more, baseline heart rate is more so dive response peaks and gives best O2 reading. After that I am not sure what happens, maybe body acclimates to high CO2 level so "feels" better and is reduced dive response or maybe just body gets tired so uses more O2 and O2 reading drops. I have done this type of interval training sometimes for 60 minutes just to see what would happen, would O2 drop off more and more and it doesn't, it kind of reaches plateau and hovers there, maybe between 65% and 75% minimum.

So anyway these are my theories and some more data for you to contemplate. Congrats on your WR's, I am big fan of yours (though am training to break WR in DNF with so watch out!!).

Cheers Wes Lapp

 

[Mullins]

Thanks Wes - forgive the short post, I'm just off to the pool: so if John wanted to do a max dive, based on that data you'd advise him to do it after 2x50m warmup dives? If not, why do you think the higher reading on that third dive would not translate directly into performance, given what you say below:

On the second interval the dive response happens faster, the initial heart rate is more, there is more latent CO2 so dive response is more quick and this saves core blood O2 levles. On the third interval CO2 is even more, baseline heart rate is more so dive response peaks and gives best O2 reading.

Just wondering how you'd resolve the apparent contradiction between no-warmup dives maximising performance; and warmup dives yielding genuinely higher O2 readings.

 

[TRITON]

Dave, when you did 8:11 STA at the WC in Sharm , did you do any warm ups and when did the contactions start?
I have done a lot of experimenting with warmup/no warmup statics and found that when doing no warm up statics contractions come much sooner( at about 1:30-2 min) and because of that I couldn't reach more that 4-4:20 without warm up...

 

[Mullins]

I never train statics and don't like them very much, so for the WCs I made it easy for myself by doing 2 exhale warmups and hyperventilating. This meant contractions came late, at about 3:40 I think.

 

[KatFish]

Dave, when you did 8:11 STA at the WC in Sharm , did you do any warm ups and when did the contactions start?
I have done a lot of experimenting with warmup/no warmup statics and found that when doing no warm up statics contractions come much sooner( at about 1:30-2 min) and because of that I couldn't reach more that 4-4:20 without warm up...

If you keep on with them it gets better. I only do no warm up max statics now. On a good dive contractions are starting between 3:30 - 3:50 and I'm not having many pre 5 mins. I don't alter my breathing prior at all and do minimal stretching. I can't pack fully with them though - about two thirds of my full pack - need to stay really relaxed. I find them better as I can fully zone out pre-dive and get into a great mental state. I just put my head on the side of the pool and know it's going to be good when I almost fall asleep... zzz My head is so clear at the end (which I'm still finding), it's amazing.

 

[wes]

Dave,

No worries on short post, I run mfg company and have a 4 year old!!

so if John wanted to do a max dive, based on that data you'd advise him to do it after 2x50m warmup dives?

Based on my experience and what I have read on DP I would advise John to do a no warm-up, no breathe up inhale and go, assuming he could (thru training or mental toughness or both) resist the urge to stop during the onset of his dive response.

I also want to point out that the interval training I was doing with John was designed to keep him in the zone of onset of dive response while at the same time being able to show him he had plenty of O2, by giving him SAO2 readings in between intervals. I am not sure if this trains the dive response to come sooner (I think it does though have no data to support this) though I am sure that training in this way allows people to get used to this no-warm up way of diving fairly easily as they experience the dive response onset alot. So my complete recommendation would be to train repetitive shorter intervals and work on enduring dive response and technique and then do max attempts first time no warm up style.

I have also found that to train people who get "stuck" coming up say always at 50m, have them do 50m and a 10 second hold at the end then 50m and 20 sec hold then 50m and 30 sec hold as they train day after day. If you think fighting the urge to come up during dive response is tough then try coming up into the air at the end of the pool and not breathing for 30 seconds, that is really tough. I always tell people if you can do that then for sure you can go another 25m (even though phsyilogically its not quite the same) because if you do this practice much, holding for 30 seconds after coming up at the end you will know its very very tough to do, and if next time I say, OK now turn at 50m and go to 75m you for sure will turn at 50m instead of coming up to do another 30 second hold!!

If not, why do you think the higher reading on that third dive would not translate directly into performance,

That is an excellent question. Lets assume that the 85% SAO2 reading at the finger tip after the 3rd interval did correspond to higher core blood SAO2 levels and ask if this would mean better ultimate performance? I would say it would not. I would prefer to explain it using a mathematical model of a trained freediver made from extensive data though these aren't available so will explain it by saying some of my theory: The dive response comes on much sooner and stronger in the third interval because the body is already so tired and not recovered from the 1st and 2nd dives. Lets say during the first interval the dive response doesn't happen until 50 seconds so only last 5 seconds of 55 second 2x25m is dive resposne and first 50 sec is not. The body then during the first 50 seconds "gladly" sucks the O2 out of the hemoglobin and doesn't work to preserve it until its already below 80% and if this dive continued the drop in SAO2 would flatten as the dive response kicked in and the body did shunting and tapped other O2 stores like creatine and hemoglobin and spleen squeeze so you would end up with a good result.

Now on the third interval the baseline heart rate is up, the CO2 levels are already high, the creatine and myoglobin reserves are partially used up and there is maybe even some latent adrenaline in the blood from resisting dive response on previous intervals. So as soon as you push off the wall and maybe 25 sec into your dive you get dive response very quick and hard and you already have extra hemoglobin from spleen squeeze circulating in your blood so you go for 30 seconds this way, you get shunting and core blood recirculation etc so after 55 seconds you are at 85% SAO2 which is great except you have no reserves, your creatine , myoglobin are shot, you have no extra oxygenated hemoglobin in your spleen and your muscles already have lactic acid from previous intervals so if you decided to keep going your 85% SAO2 would fall off much much quicker than your previous 80% giving you a worse perfoamance maybe with some early muscle failure from lactic acid build up, or cramps etc.

So what you want is to signal to your body to do the dive response without having to deplete the stores first. Doing exhale or full negatives partly does this because there is so little volume of air in the lungs the CO2 concentration rises really really fast before the SAO2 really has time to fall using up any stores. Also psychologically thinking about panic or fear can trigger dive response sooner, same with facial immersions and sinus flooding.

Even better would be to leave and exhale all air into a bag then have dive response come after 10-15 seconds then slowly inhale the bag keeping the dive response up and replenising oxygen from the bag. This isn't allowed in comp of course though maybe something spearos might work on?

Cheers Wes

 

[rxcnc2]

...
resist the urge to stop during the onset of his dive response.
...
If you think fighting the urge to come up during dive response is tough
...

What do yo mean by the dive response, do you mean contractions?

 

[wes]

What do yo mean by the dive response, do you mean contractions?

Hey,

It's a bit complicated and not sure there are any agreed on definitions though this is how I mean it in the theory I am saying.

When you start a static or dynamic and hold your breath your body slowly uses up oxygen from several sources, blood, lungs, and more. At some point your body figures out it is getting low and things happen that reduce the rate of use and the effect of these things is to make the oxygen last longer. In general the things that your body actively does to reduce the rate of oxygen use are called together "dive response" or "mammalian dive response" or "dive reflex" or "the mammalian dive reflex" and these all I think mean the same thing. There are many things cited as dive reflex including vascoconstriction which is the tightening of blood vessels to reduce blood flow and thus oxygen use to arms and legs and spleen squeeze which is when the spleen is squeezed by muscles and releases extra hemoglobin in the blood (some evidence/controvercy that this hemoglobin is oxygen enriched when released). Now the way I see it anyway, there are other things that happen to prolong apnea that aren't really active things the body does and I wouldn't call them dive response though they do help, for example when CO2 builds up in the blood this shifts the Ph index (acidity) of the blood and helps the hemoglobin release oxygen which prolongs apnea. The body doesn't do anything active for this to happen though, it happens as our body releases CO2 so could be called dive response or not. I would not include this in dive response. Now there is something called the "urge to breathe" which is a psychological term meaning how much do I want to breath and in the old days a concept called the "break point" which meant the point at which one "had to" come up for a breath, with the theory that one couldn't really hold ones breath to black out like now we know people can. So now when you get that feeling that you have to come up for air we don't call it the break point we call it experiencing the urge to breathe.

Another thing is contractions and this is also an active thing the body does when the CO2 level rises during a breath hold and this thing is generally not considered a dive response as it does not prolong the dive and in fact uses up oxygen so shortens the dive and some people have strong contractions and some weak and some none at all and some who have none at all do really really well at freediving though I don't know any reports of anyone figuring out a way to train not to have contractions and many reports the more you train the stronger you contractions get. To make things more complicated dive response is also triggered partly by CO2 build up so is linked to contractions and dive response also is claimed to be trainable to come more strongly and there is alot of evidince dive response lingers for up to 12 hours after diving so in the old days many divers would do thier best statics always in the evenings after a days deep diving. Now people do warm ups for static that mimic long dives and stimulate dive response that lingers on into their competitive holds and helps their max attempts.

So throwing all this together, and I will not say this theory is proved or not or even supported by much evidence, though I will say its my current working theory and give it out to help people understand how I would use these terms together:

In static many people do warm ups which in various ways expose them to CO2 build up which causes some body response and which affect lingers and there is some pauses and then a competitive max attempt is made. I think the main affect of these holds is to desensitize the body to CO2 so the body ignores it more and thus delays contractions and the urge to breathe. I would not say this is mammalian dive response as it does not shunt blood flow much to limbs and delays contractions indicating the body is not reacting to the apnea hold or CO2 build up or O2 loss. This is beneficial in that it keeps contractions from happening which use up lots of O2 and gives longer holds. The down side is doing the warm up holds can cause the body to use up stores of O2 that aren't fully replaced like creatine or myoglobin which means starting on less than a full tank. Also regardless if this causes vascoconstriciton or not it doesn't matter much as your arms or legs should be totally still during static so wouldn't use up O2 anyway.

Tom Siestas (a top static person) doesn't apparently get contractions so it would make no sense for him to do warm up holds to delay them especially if these warm up holds took away some O2 strores for him.

Now for dynamics it is very different. The arms and legs are being used so vascoconstriction helps a ton as it limits O2 sent to the arms and legs and they use anerobic process for power that doesn't use O2 so the sooner and more intense vasconconstriction the better. Also getting contractions or not does not matter much as the hold is much shorter 3-4 minute for top dynamic vs 8-10 min for top static, and the dynamic overall energy use is much higher so adding a bit for contractions doesn't change outcome much compared to static. So a top strategy for dynamic is to not do any warm up and even breathe very slow and maybe build up CO2 a bit before the dynamic starts so then in dynamic the dive response happens very fast, maybe starting after 30 seconds as the CO2 levels starts higher and gets high very fast so contractions happen faster and dive response happens faster and in the middle of this maybe at 60-90 seconds the urge to breathe is really really hard to ignore and there is some phychological things that happed too, paranoid thoghts come into minds, some people see they are going to die or are killing their brain cells or have thoughts they are damaging them (I have had this happen even though I "know" the evidence does not support this). Many trained top athletes sometimes stop at about 1/2 their personal best because they cannot go on with so much dive response and come up for air in "the middle" of their planned dives (I have done this too) so this is the drawback of this method.

Anyway hope you found this theory interesting and main point is not to say its for sure right or wrong, rather to give you some sense of how dive response as used alot on DB as it relates to contractions and the urge to breathe (though of course its OK to say this theory is right or wrong!!)

Cheers Wes Lapp

 

[TRITON]

I have read somewhere that Tom does experience contractions and they come at about 3:30-4mins...

 

[TRITON]

If you keep on with them it gets better. I only do no warm up max statics now. On a good dive contractions are starting between 3:30 - 3:50 and I'm not having many pre 5 mins. I don't alter my breathing prior at all and do minimal stretching. I can't pack fully with them though - about two thirds of my full pack - need to stay really relaxed. I find them better as I can fully zone out pre-dive and get into a great mental state. I just put my head on the side of the pool and know it's going to be good when I almost fall asleep... zzz My head is so clear at the end (which I'm still finding), it's amazing.

I wish that my contractions come at 3:30-4min......but I usually experience them at 2min maybe 2:10.....this is without warmup....

 

[rxcnc2]

Hey,
At some point your body figures out it is getting low and things happen that reduce the rate of use and the effect of these things is to make the oxygen last longer. In general the things that your body actively does to reduce the rate of oxygen use are called together "dive response" or "mammalian dive response" or "dive reflex" or "the mammalian dive reflex" and these all I think mean the same thing.

Yes it's the diving reflex. But what I find confusing is that you want to "fight it", that's why I thought you were talking about contractions.
The diving reflex starts relatively early - difficult to define and it depends whether we are talking about deep diving or static - but I would say generally within the first 30s or 1' that your face is in the water. I am not sure that it has to do with low oxygen, in fact I think it has to do more with your body being in the water and particularly your face and the neck. The diving reflex is generally a good thing, people want to facilitate it not fight it. I am sure that a search through the literature (try trux' apnea.cz) will dig out better definitions.

Contractions are the signal and response to high CO2 in your blood, that's something that you have to fight (knowing what you are doing of course or you'll blackout) if you want to stay longer.

About Tom Sietas, as far as I know and have seen, he does get contractions and actually relatively early (say within 4', when he's doing 10' STA).

 

[wes]

RX,

Yeah, thanks for the reply and I agree with your points. For me I don't really "fight" contractions as much as I "fight" the urge to breathe. Sometimes contractions are really strong and I don't really feel any urge to breathe, other times even when contractions are pretty mild I get huge urge to breathe on dynamics so I guess I connect the urge to breathe with dive response and contractions don't seem to bother me much. That is what I meant by fighting dive response, I should have said fighting the urge to breathe that I associate with sometimes having very strong sudden dive response.

I have not done any experimenting with no warm up statics though it sounds good for some who have tried.

Cheers Wes