She could swim two kilometres in a pool without stopping. Comfortable, relaxed, good technique. In a lake in May she got forty metres from the bank, turned round, and came back, and she was genuinely shaken by it.
She told me she had panicked, and she said it in the tone people use when they are describing a personal failing.
She had not panicked. Her body had done exactly what it is built to do when cold water hits it, and nobody had told her it was coming.
Cold shock is not fear. It is a reflex, and it has a timetable.
What Is Actually Happening
Cold water on the face and chest triggers an immediate, involuntary response. An enormous gasp. Breathing rate spikes to several times normal and you cannot voluntarily slow it. Heart rate and blood pressure jump. There is nothing you can do about any of it by deciding to be calmer, because none of it is under conscious control.
It peaks in the first thirty seconds or so and it substantially settles within two or three minutes.
Now put that inside a person who has never felt it. They are hyperventilating, their heart is hammering, they cannot get a breath, they are a long way from the bank, and they are surrounded by people. Every one of those sensations is a signal your brain reads as danger, and it produces exactly the conclusion you would expect.
The panic is not the cold shock. The panic is the interpretation of the cold shock by somebody who does not know what it is. That is why knowing about it helps so much, and it is the first thing I tell anybody going into open water.
Why the Wetsuit Makes It Worse Before It Makes It Better
A wetsuit is a squeeze around the chest. For the first minutes in the water, that pressure plus a breathing rate you cannot control produces a very convincing feeling that you cannot expand your ribs.
Almost every experienced open water swimmer has had a moment of thinking their suit is too tight. It usually is not. It is that a restricted chest and hyperventilation feel identical to being unable to breathe.
Check the neck rather than the chest. If the collar is tight enough to be uncomfortable when you turn your head, that is worth fixing. Chest tightness in the first two minutes is nearly always the reflex.
How I Train It Out
Habituation, which is the dull word for repeated exposure until the reflex stops firing so hard. It works, it works reliably, and the research on it is clear: a handful of short cold immersions substantially reduces the response, and the effect lasts for months.
Five or six sessions is enough to make a large difference. That is the entire intervention.
What I actually ask for. Get in slowly, to waist depth, and stand there. Splash your face and the back of your neck. That is where the receptors are densest and where the response is triggered hardest. Then put your face in and blow bubbles, standing up, feet on the bottom. Then repeat, twenty or thirty times.
Only then start swimming, and swim slowly, close to the bank, parallel to it, breathing every two.
Give it three minutes before you make any judgement about how the swim is going. That is the single most useful instruction I give, because the first three minutes are always the worst three minutes and people quit inside them.
On Race Morning
Get in beforehand if the race allows it, even for ninety seconds. Face in, a few strokes, let the reflex happen while you are standing in shallow water surrounded by nobody. Then it has already been used up by the time the gun goes.
If you cannot get in, throw water on your face and neck before the start. It is a fraction as effective and it is better than nothing.
Start at the back and to the side. Being swum over while hyperventilating is what turns a manageable reflex into a genuine emergency, and thirty seconds of position is a trivial price.
And go out slower than feels right for the first two hundred metres. Everything about the situation will tell you to go hard. Do not.
What I Tell People Who Have Had a Bad One
That it will happen again if nothing changes, and that it is not a character problem.
An athlete who has had a frightening open water experience now has two things going on: the reflex, and a learned association between that water and fear. The second one also responds to graded exposure, in shallow water, with somebody else there, in a way that never gets alarming.
Going straight back to a deep lake and trying to be braver about it is how people end up avoiding open water for years.
The Bottom Line
The gasp, the racing heart and the breathing you cannot control are a reflex, they peak in thirty seconds and they settle in three minutes.
Get in slowly, splash your face and neck, blow bubbles standing up, and do that five or six times across a few weeks. Then get in before the start on race day and give yourself three minutes before deciding anything.
