Heart rate control

[Antoine]

I was wandering if anyone on this forum knows of ways to control heart rate to certain extent, both before and during apnea.

As discussed in another thread, lowering your HR is only useful during anea so I was wandering if someone knows how to, perhaps, conciously raise your HR slightly before apnea to help oxygenate the body and lower it during apnea in order to lower the consumption of oxygen.

I personnaly can slightly lower my HR by relaxing very deeply although I can only lower it after a certain period of relaxation and only if I am completely still. I know there are yoga methods of controling HR and I am interested to hear them but does anyone know the "science" behind HR control?(if there is any)

Thanks,
Antoine.

 

[Mr. X]

One way to control your heart rate when not holding your breath is by controlling your breathing, specifically slowing it down. I've done this while hooked up to a blood pressure meter and was able to reduce my blood pressure, as well as my heart rate, significantly by slowing my breathing - my wife tells me off for doing this and says "its cheating"

While diving on a held breath, being calm and relaxed seems to help a lot. Yoga can help with that. Also diving a lot. I find my depths & bottom times naturally increase significantly over the course of a multi-hour spearing dive and towards the end of the spearfishing season. You just get more used to everything, your gear, "systems" and mindset become sorted and you relaxed. You don't need to think about things as much as the drill becomes second nature. Then you loose most of it over the winter and start again the next season

 

[Siku]

Stress, fear, etc can raise heart rate even during inactivity (e.g. at a comp). I think this was the idea behind Seb Murat's stressed diving.

Bradycardia during the dive is part of the MDR so this will strengthened by training, as Mr. X says.

Does having a higher heart rate before the dive encourage bradycardia once the dive starts?

 

[FreeRestriction]

I think there might only be a couple ways to truely raise the heart rate without raising oxygen consumption with it. And again im not a doctor but my guess would be to be in great fear where adrenaline is released and your hearts "preparing" your muscles for the fight or flight. The problem would be immediatly reducing it once you dive.

My theory (which may be totally wrong) is that you cant gain anything by raising your heart rate because your just raising your oxygen consumption unless your scared or something. Ill give an example of the opposite side. If a yoga person can lower his/her HR they are just lowering their bodies demand for oxygen. If this wasnt true then theyd essentially be able to kill themselves by lowering their HR below what their vital organs need and i dont think thats the case.

So Antoine you say you can lower your heart rate if you dont move. Thats because your reducing your oxygen consumption so your HR follows. The key isnt to lower the HR the key is lower oxygen consumption. Or raise HR some how without raising oxygen consumption.

So i dont see how a raised HR and equally raised oxygen demand would be a benefit even if you could reduce the HR immediatly upon starting the dive.

 

[growingupninja]

Stress, fear, etc can raise heart rate even during inactivity (e.g. at a comp). I think this was the idea behind Seb Murat's stressed diving.

Bradycardia during the dive is part of the MDR so this will strengthened by training, as Mr. X says.

Does having a higher heart rate before the dive encourage bradycardia once the dive starts?

High hr before a dive, due to stress but not actual O2 demand, is I think a big part of seb's theory. Worth noting though is that he is not engaging in serial diving.

I know for me bradycardia comes on much, much faster during the first few holds of a session, but I am not approaching the hold in an aprehensive state. These will also be the most metally challenging and uncomfortable. The hypoxic threshhold to trigger my dive response increases throughout a session. Holds feel more comfortable but are usually actually more hypoxic...although I sometimes get into a good zone where O2 consumption seems reduced although I am not experiencing the same level of bradycardia. Important for serial divers/spearos.... On tough sets where I am repeating dynamic holds at near max there is a fair bit of variance in O2 consumption and I have yet to figure out all my triggers.

 

[Antoine]

Thanks guys, very helpful

 

[Ms Mer]

I've played around with my HR monitor in the past and consciously trying to lower my HR through breathing, relaxation and mentally focusing on dropping it. Interesting experiment. I have a fairly low resting HR anyways but it's kinda fun to try and lower it more and shows that one can consciously do it, even when under stress. I start yoga this week so am interested in finding out what that may do also.