Mammalian Dive Reflex

[hulagirl]

For my open water swim friends.

Do you find yourself gasping for air as soon as your face enters the water? Does it feel like your heart is racing and no matter what you do you can't catch your breath? Does it feel like your chest is tight and your arms weigh 2 tons?

This is the Mammalian Dive Reflex and I am CURSED with it.

Does anyone have any tips/tricks/words of advice on how to control it? I tried dunking my head into the water on Tuesdays swim. Instantly I began to shiver uncontrollably. By 500m I am usually calming down, but Tuesday was hell. It got worse and worse and by 800m I was either going to pass-out or my head was going to explode. Horrible swim.

This happens to me in a heated pool as well as open water. The pool version of it is not as bad. Maybe lasts 100m max. And I usually get through it with a kick board warm up. Also happens when I snorkel.

I have found only 1 article that relates to MDR and open water swims. It's a common thing that is dealt with in SCUBA diving. I read that it's a 30-45 min "symptom" that the body goes into!

Anyone have these same issues?

ETA: Hawaii is blessed with warm water so no wet-suits are allowed here. I do wear a rash-guard when I swim to help stay warm. I would guess the water temp is not below 70 right now. Pool is about 78. Air temp is 78-85.

Denise

[KnottedYet]

I just don't put my face in the water...

...seriously.

I've always swum with my face out of the water. I'm a slow swimmer anyway, so it doesn't matter. Mine is more a panic. Had a bad experience diving once (rip-tide, clinging to a rock, running out of air) and really get perturbed if my face is under now.

MDR slows the heart rate, reduces bloodflow to the extremities, etc. What you describe sounds more like a panic. The active reflex is to help us survive under water, it doesn't make us fight to get out of the water. MDR is what makes itty-bitty babies so calm and happy underwater.

Here's an abstract: http://www.springerlink.com/content/l831603655v86219/

Here is a paper by some folks who posit that the MDR's slowing of the heart rate could somehow be used to help calm a racing heart rate. http://www.sciencedirect.com/science...c&searchtype=a

I can't get the full text of this one, but it talks about how emotional arousal can counteract the calming and heart-slowing effect of the mammalian dive reflex - that would be the panic you and I experience which prevents us from experiencing a proper MDR. http://onlinelibrary.wiley.com/doi/1....cp020325/full

[hulagirl]

Knot - check out this blog:
http://www.internalmonoblog.com/2011...ld-water-swim/

Specifically:


"In the swim leg of the race, you may experience diving reflex as the feeling of the inability to breathe, gasping for air, the closing of the throat, cramping and panic. Clearly something you want to avoid Fortunately, you can prepare yourself for the shock and teach your body to handle it in a manageable way."

I suppose I should have noted that I do not have this happen to me in warmer water temps. As the temp goes up, I have less of a response. Shallow or deep, flat or rockin, the severity depends on water temp and air temp.

There is some panic that kicks in AFTER MDR starts - that's for sure!

[KnottedYet]

He's wrong.

MDR holds the breath, slows the heart, calms the nervous system, and redirects blood from the extremities to the core and brain.

It does not cause panic nor cramping, nor gasping.

The negative effects you, I, and he experience are from panic. MDR causes bradycardia, not tachycardia. It is deliberately evoked during some surgeries to calm the patient's body.

If we could get over our panic at experiencing the reflex, we'd be fine. But he's blaming MDR for something that is NOT caused by the MDR. You don't train your body to get over the MDR, you train your body to not panic. MDR is your friend in the water, and you cannot "train" it away, it is a reflex.

ETA: yes, MDR is stronger in colder water. Cold water sucks heat out of the body quickly, so it behooves the body to step up the automatic response a bit. Training yourself to get used to the feeling of the MDR so you don't panic is probably best done in colder water, since that stronger reflex is the one that sets your body into a fight-or-flight. Or you could just do like me, and never put your face in the water...

[HillSlugger]

Cold water on the face tends to stimulate a gasp reflex that can make it hard to breathe and easy to panic. I've dealt with that, and it's something you can get used to. Splashing cold water on the face, dunking the head, etc can prepare the body and reduce the reaction.

Something else I've dealt with is "freak out on go" syndrome Starting out too fast, getting out of breathe, and then panicking.

[Catrin]

This is why I never learned how to swim, outside of the back stroke Part of me would like to, but I just can't put my face in the water without panicking...

[Biciclista]

This is why I never learned how to swim, outside of the back stroke Part of me would like to, but I just can't put my face in the water without panicking...

Catrin, I won't ask how you wash your face...

[lph]

I'm curious if those of you who have this strong reflex have ever tried swimming with a diving mask? I ask because I used to be a bad swimmer and didn't like deep water, much the way people are afraid of heights. I was also unable to be under water without holding my nose, sooner or later I'd do the gasp-in thing. This all changed when I tried snorkeling in shallow water with a mask (I could SEE what was down there!), and in recent years I've become a passable swimmer too. I still have to wear a mask or goggles and nose clip, though. The really great thing about snorkelling with a mask and snorkel was having so much time, I learned I could just relax and look around and still breathe all the time.

[Catrin]

Catrin, I won't ask how you wash your face...

LOL, of course it isn't the same thing

[Crankin]

I can't put my face in the water for more than 2 seconds. Nor can I use a mask. It's a feeling of of total claustrophobia, panic, and feeling like I am going to die.
I can swim, but obviously not really fast, because I don't like the breathing part. I also wear contacts, so that's another reason for not putting my face totally in the water. I can't use goggles, either. Anything that takes away the feeling of having all of my senses, i.e. breathing the normal way, seeing totally clearly, freaks me out.
I didn't learn to swim until I was 7 or 8 because of this, even though I spent all summer at the beach and 2 years in day camp. I also won't swim in water where I can't stand up, except in a pool, but then I have to be very near the edge, so I can grab ahold of something.
I have a real fear of drowning, not being able to swim the distance, even though I know I have cardio endurance. Many years ago, I had a stress fracture in my foot, from teaching too many aerobics classes on a concrete floor. The only thing I could do was swim. It was September in AZ, so I got up a 4:30 AM to swim for 30 minutes in my own backyard pool. But even that freaked me out. I had to put on all of the floodlights and put the radio on, or else I felt like I was being enveloped in something that was going to do me in.
It's amazing that both of my kids are excellent swimmers and my younger son has the highest swim classification that you can get in the military.

[lph]

I can't put my face in the water for more than 2 seconds. Nor can I use a mask. It's a feeling of of total claustrophobia, panic, and feeling like I am going to die.

I can understand that, it's not a great feeling wearing a mask and breathing through a snorkel, it feels a bit constrained. I just mention it because to me the mask took away a lot of the feeling of having my face in water at all, it felt "protective". So once I got somewhat comfortable with wearing a mask and breathing through a snorkel on dry land, putting my face under water didn't make much difference.

[hulagirl]

Over the past few days I've done a lot of testing!

1. I ran 1.5 miles from my house to the beach before I got in. I expected the ocean to be calm that day as the winds were down. I didn't check the surf report. Duh. This dork swam in 2' waves and chop. Turns out the wind was blowing at the beach, just not my house!

I fully expected to freak out. Chop/waves are not my friend and I avoid them when I can. However, I did not have any panic, breathing issues. The water felt warm and oh so wonderful to me! Yes, I had some fun free-falling and a face full of water numerous times. But I just laughed and tried not to get sea sick! No gasping, no racing heart. It wasn't an easy swim, and when I turned around and headed into the wind/waves it was much harder and I had to stop.

+ 1 for elevating my heart rate with a hard run before getting into the water. Seems to help.

2. On Saturday I swam at a lagoon on the other side of the island. Calm, flat, no wind. Ran 1 mile before the swim, got nice and hot, high heart rate. But the water felt much colder and I started to get chills and began to shiver before I could get my chest in the water. Head in and I was doing the gasping thing. Keep in mind that this is FLAT water that I can stand up in. There is no panic here. There is no fear of the water. It is a response my body is kicking up due to cold water temps.

I swam with my coach and she had me do controlled breathing exercises for 100m. At 100m I did more stroke work and had horrible issues with inhaling water. I can't control the gasping underwater so I suck up water before I can come up for air. At 200m I continued to do more stroke work, concentrating on breathing every 2 strokes, then switching sides. At 300m I began to be able to control my breathing better. At 500m I was better. And was able to swim another 500 only having to stop for breath twice. (not because I was gasping, but because I was just tired!)

Of the 2 swim sessions my body was MUCH colder on Saturday. The water in the lagoon is probably a colder temp and it was early in the day.

I do not believe it is panic related. If I was going to panic it would have been on Friday in the 2' waves and chop. Not calm, flat and only 5' deep.

And I do get this when I snorkel for the first 15-20 min. It's so not fun!

[Cataboo]

Hulagirl, I think the problem is that what you are calling the mammalian dive reflex is not what you are describing - you're describing the involuntary cold water gasp reflex. Both happen as a reaction to cold water, but they're not the same process.

I don't swim really, but I know as a kayaker, we're all warned strongly about the cold water gasp reflex and the panic that it can cause, even if you're wearing a drysuit and should be fine in the water temperatures. The other thing to worry about is cold water getting in the ear canal really can do a number on your balance.

Links:
http://www.oregon.gov/OSMB/safety/co...mmersion.shtml
Four Stages of Cold Water Immersion

Stage 1 -Cold Water Shock
When someone falls into cold water their first unconscious response is to take a large breath of air, called the "involuntary gasp reflex." If their face is in the water when that gasp occurs, then their chances of survival immediately diminish.

http://www.ussartf.org/cold_water_survival.htm

I also find it funny that Hulagirl quoted a blog and Knotted yet is quoting scientific articles.

[hulagirl]

I also find it funny that Hulagirl quoted a blog and Knotted yet is quoting scientific articles.

I'm glad I could be of entertainment value! Once you suffer through a shitty 2000k swim like I did, you are desperate to figure out what is wrong. Finally finding someone that specifically wrote to my issues - blog, scientific, whatever - was such a relief.

Being told I'm 'just panicking' is much different than being told that what I'm having is called "Cold Water Shock." There is a HUGE difference. One you can control with time, training, focus, and experience - the other, you can't (well, at least you can't in a triathlon that bans wet-suits!).

Thanks for the link. I have to figure out a way to keep my core temp warm and my heart rate elevated so that I can feel good when I get in the water! LOL!

[KnottedYet]

I never said you were "just panicking."

I was pointing out that what you and the blog-dude and I experience is not from the MDR.

Cataboo found our culprit: a cold water reaction that makes us gasp and panic. (and I'm not talking about a cognitive panic, I'm talking about physiological panic, the arousal that the third paper I linked said could override the effects of the MDR and cause tachycardia, etc.)

Clearly the solution is to hang out in nice warm water... with a floatie and a beer for me!