how low can you go

This post is by way of an ice breaker on the subject of swimming in very cold water. Before this winter I was almost completely ignorant on this subject. The weather and my purchase of a season ticket at Parliament Hill Lido were the two things that conspired to make me get the inside track on it.

By mid November the water was down to 7C in the lido. I don't know if you have ever swum in 7 degrees, but at that time I found it pretty bracing.

Sunrise, mist and a toasty 7C

 I was swimming about 2k or more most days, which was my usual distance indoors. I began to think I would be able to train outdoors all winter and decided not to use the indoor pool any more.

No sooner had that thought crossed my mind, than the temperature dipped. Each time it went down it was a first for me. 7 days later it was 4C.

I wanted to keep up the distance as much as possible, to test my limits. I wanted to hold stubbornly onto the idea that I could stay fit with nothing but 2,507,000 litres of cold water, a lido, trunks, a silicone hat, some earplugs and a pair of goggles.

At 4C I struggled to swim 1k, let alone more. I felt like I was right on the limit. Regulars looked at me in a funny way. If you have been to PHL in winter, you will know that regulars look at you in a funny way anyway, but that's just how they are and they don't mean anything by it.

But this was different. They seemed to think I was an outright mental defective (and frankly, in the nicest possible way, that's rich coming from some of them).

Nobody there swims anything like that distance. I became fascinated to know more about the effects of swimming in cold water. The difference acclimatisation made. How low can you go. And how far.

Inner light and very sharp teeth

There is a distinction between cold water and, if you will excuse my use here of a scientific term, ice, or really fucking cold water. And it is subjective up to a point, although extreme cold is something most people can agree on.

The International Ice Swimming Association defines an ice swim as one taking place in water below 5C. And that's probably a reasonable appraisal. Mind you at this stage I hadn't even heard of them.

Most open water swimmers would say cold water is below about 14C. 'Normal' or occasional holiday swimmers would probably say less than 19 or 20C is pretty cold. Lido and other open water winter swimmers generally say under 7C is a bit parky. 6C down to 0C is in the realms of the icy. And each degree drop from 6C is exponentially more brutal and debilitating.

Cold is a curve ball thrown in with the more predictable factors- ie: fitness, breathing, technique, stroke rate, and so on.

Cold doesn't exactly make a nonsense of all of the above, but it does shake it all up a little and put a  different spin on the idea of going for a short swim.

Hypothermia is a ticking time bomb- it is inevitable that your core temperature will drop, it becomes a question of how long you can continue and what it will cost you in terms of recovery.

November wore on and the temperature stayed at the 3 or 4C mark until just before Christmas.

In the mean time I got used to doing my 17 lengths (1,080m) at that temperature. Observed how my body responded as I embraced the cold water and felt its icy grip tighten around me. How long it took to recover. How to arrange my clothes so I could put them on quickest.

Crucially, and importantly, I was able to do all this without fear or panic and with a scientific detachment as I learned what to expect, what I could do, and my confidence grew.

122m of cold shock response, tightening chest, ice cream head, skin burning like being dropped into a deep fat fryer. The 480m before the body numbs and I settle into a comfortable rhythm. The tightening of the nerve in the elbow, stiffening of the muscles in the arm, the feet and hands numbing. The tendency for the stroke to disintegrate for the last couple of laps as desperation settles in and I just want to get out.

I made 'relax' my mantra, relax chest, breathe out, relax arms, one, two, three, breathe out, relax wrists, hands, one, two, three, relax neck, notice any tension, release it. Keep the stroke consistent, relax, arms parallel, don't worry, relax, don't rush, relax, conserve energy and heat.

Oh and relax.