Dive reflex not always helpful?

[naiad]

I have been doing dry and pool training for a long time now, and my dry apnea performance is always significantly better than in the pool. I have tried to work out what the reason is, but nothing fully explains it.

- Posture - I am in a lying down position for both, I lie on my side for dry static. I do not do either in a sitting or standing position.

- Suit - The effect is the same in static or dynamic, and seems to have little to do with a restrictive suit.

- Fear/stress - I am not normally scared or stressed during pool training. My stress levels are about the same for both.

- Absorbing O2 through my nose - I don't normally use a noseclip for wet or dry static, but I tried dry statics with nose pinched and they were still much longer than my wet static PB.

- Cold - My performance is much worse when I am cold, but I am not always very cold during training.

The only thing I can think of that could cause the difference is the cool water on my face. If I am doing dry statics in even a slightly cool room, it has the same effect as the pool.

Maybe the dive reflex is having a negative effect?

[cdavis]

Could be that you may inhale a good bit more air doing dry static, more o2 plus more volume to dilute the c02. For me its somewhere around .5 l (face down). That is significant in percentage terms.

Connor

[Mullins]

Are you blacking out or getting LMC earlier dry than wet? Or is it just a subjective judgement of how you're feeling?

[azapa]

my two pesos: in pool statics you are surrounded by people, dry you are at home by yourself?

The second would be more relaxing i assume and you would be starting it in a more relaxed state. The former, you may have already (earlier) done some warm up lengths of the pool, and all though not feel depleted, may be a little, that combined with the peer pressure, anxiety etc takes its toll?

[efattah]

Here are two reasons:

1. Oxygen absorption through your skin
- Your skin absorbs a lot of oxygen, up to 8% of your body's requirement. Underwater this is not the case.

2. CO2 storage
- Under conditions of vasoconstriction & cold, your CO2 storage capacity is reduced. This requires you to modify your diet, training or breathe-up to compensate. If you use the same diet/training/breathe-up for wet static and dry static, then your wet static time will be less. This is the main reason that wet static is a totally different event than dry static, and requires its own training & optimization.

[naiad]

Thanks for all the replies.

Originally Posted by cdavis

Could be that you may inhale a good bit more air doing dry static, more o2 plus more volume to dilute the c02. For me its somewhere around .5 l (face down). That is significant in percentage terms.

I have tried packing with both, and my dry static PB without packing is much longer than my wet static PB with packing. In fact my best times have been done without packing, and I can gain about 1l with it.

Originally Posted by mullins

Are you blacking out or getting LMC earlier dry than wet? Or is it just a subjective judgement of how you're feeling?

I do black out much earlier wet than dry.

Originally Posted by azapa

my two pesos: in pool statics you are surrounded by people, dry you are at home by yourself?

The second would be more relaxing i assume and you would be starting it in a more relaxed state. The former, you may have already (earlier) done some warm up lengths of the pool, and all though not feel depleted, may be a little, that combined with the peer pressure, anxiety etc takes its toll?

I never do warm up lengths or any other warm up exercise before any training, wet or dry.

Maybe I am a bit more careful because others are watching, but often I am just with one buddy, and I am quite relaxed and not thinking of being watched.

Originally Posted by efattah

Here are two reasons:

1. Oxygen absorption through your skin
- Your skin absorbs a lot of oxygen, up to 8% of your body's requirement. Underwater this is not the case.

2. CO2 storage
- Under conditions of vasoconstriction & cold, your CO2 storage capacity is reduced. This requires you to modify your diet, training or breathe-up to compensate. If you use the same diet/training/breathe-up for wet static and dry static, then your wet static time will be less. This is the main reason that wet static is a totally different event than dry static, and requires its own training & optimization.

Could be. I don't know about the oxygen absorption, I would have to measure my O2 level during both. I am usually a normal colour after a wet static or dynamic, even when I feel close to the limit. My buddies have never commented that I am seriously blue. I can get much more hypoxic, as measured by colour, during dry statics than wet, and still finish clean.

The CO2 storage could explain the early urge to breathe, but not the early onset of blackout.

[cebaztian]

Originally Posted by cdavis

Could be that you may inhale a good bit more air doing dry static,

one advantage with water is that you can get more air into your lungs.

Sebastian

[naiad]

Why? I thought it is not possible to get as much air in water because of the water pressure.

If I pack heavily, I am more comfortable in water than on land, but I don't do this for normal training.

[TRITON]

Originally Posted by efattah

Here are two reasons:

1. Oxygen absorption through your skin
- Your skin absorbs a lot of oxygen, up to 8% of your body's requirement. Underwater this is not the case.

2. CO2 storage
- Under conditions of vasoconstriction & cold, your CO2 storage capacity is reduced. This requires you to modify your diet, training or breathe-up to compensate. If you use the same diet/training/breathe-up for wet static and dry static, then your wet static time will be less. This is the main reason that wet static is a totally different event than dry static, and requires its own training & optimization.

As i understood, by changing my diet I can increase my CO2 tolerance and therefore delay contactions,right?
What should I eat?

[azapa]

Originally Posted by naiad

Why? I thought it is not possible to get as much air in water because of the water pressure.

If I pack heavily, I am more comfortable in water than on land, but I don't do this for normal training.

although not pool related you can pack more and be more comfortable in the water due to the water pressure balancing your full torso, you won't feel that "stuffed" feeling that you do out of the water. I can feel this benefit after about 10M.

[DeepThought]

Originally Posted by naiad

The CO2 storage could explain the early urge to breathe, but not the early onset of blackout.

Less CO2 - more alkaline blood - BO at higher blood O2 saturation. Atleast I think it could also be valid in this specific case.

[Ulf]

Do you use a suit in the pool? What is the water temp in the pool? Sounds like you get a stronger DR dry than wet (which is not impossible). Have you compared your heart rate wet vs dry?

[naiad]

I do use a suit in the pool. I used to train without a suit at the beginning, but it was far too cold.
Water temp in the pool is 25-28c.
My heart rate is slightly lower wet than dry. It is never very low and does not slow down dramatically during apnea.

[Ulf]

In 25-28 c water the water in the suit will probably soon reach a temp of 30 c or something like that. I would assume that is way to warm to get any decent vasoconstriction. Maybe that could explain the difference in time.

When I did Sebastien Murat’s course he made us do a test to see how strong our DR was. The test went as follows, you start with checking your heart rate, then you do a FRC breath hold (without breath-up or warm-up) with your face in really cold water and check your heart rate when you get contractions. Maybe you could try that to how strong your DR is.
If your heart rate drops about 50 % you have a decent DR and if it drops 70 % you have a really good DR. If I remember correctly, he considered anything less than 50 % pretty crappy.

[Budho]

It might be also a training specificity. If you train mostly dry static, you might feel discomfort during wet. I've heared friends talking about that. I feel more discomfort doing dry static and it is a bit longer.
Aleš