Our Changing World: Cold water swimming – panacea or peril?

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On a frosty mid-winter morning in Alexandra in Central Otago, the outside pool temperature sits at simply 3.8 levels Celsius. The grass crunches underfoot and patches of ice have been salted for security as a result of, extremely, individuals are on the point of enter the water.

This is the 2026 New Zealand and Oceania Ice Swimming Championships. To qualify as an ice swim, the water have to be beneath 5 levels. Forty-three opponents aged between 16-71 have gathered in Alexandra to compete in numerous swim fashion and size classes.

And with them is a small group of researchers from the University of Otago.

Cold water swimming appears to be more and more fashionable, fuelled partially by social media claims that it yields an enormous vary of advantages.

But as extra folks make the leap, researchers try to raised perceive what is absolutely taking place to the physique, and whether or not the advantages outweigh the dangers.

For competitor Susan Sherwen, ice swimming is about far more than the problem of chilly water.

“It’s the friendships and the community that evolves around this event and any ice swimming because you’ve got to look after each other.”

An Auckland science trainer, Susan helped set up the championships six years in the past and is a key member of the close-knit group of swimmers.

“It’s such a brutal environment,” she says. “You often need someone to help you get dressed. That’s the sort of intimate contact that just builds really strong bonds.”

Her science background and her previous involvement organising the championships are why she additionally put her hand as much as be one of many analysis members for a University of Otago research.

Exercise physiologists Professor Jim Cotter and Dr Kate Thomas have an interest to see whether or not peoples’ perceptions of how chilly they’re and their stage of consolation line up with their precise core temperature.

Kate says: “That’s important because there’s a lot of evidence around how cold people get and it’s very variable, very dependent on body shape and size and experience. But how their feelings align with that is less well known.”

One concept, which Jim and Kate developed from observing a weekly swimming group known as the Frozen Seadogs in Dunedin, is that extra skilled swimmers are much less more likely to understand simply how chilly they’re getting as they construct up a tolerance. Thus, growing the danger of affected by hypothermia.

To examine this, Susan and different members accomplished questionnaires about their swimming expertise, had their physique composition measured, and swallowed a core temperature capsule a number of hours earlier than the longest race of the championships – a one kilometre race, which might see opponents within the water for slightly below 20 minutes.

Masters scholar Riley Gould is poolside throughout the race, taking measurement of the opponents’ stroke fee.

She then follows up with members within the designated restoration room afterwards, asking about how chilly they really feel and their consolation stage with the chilly, as they sit shivering, trying to heat up.

Due to a phenomenon referred to as ‘afterdrop’, that is when the physique temperature is at its lowest.

Professor Jim Cotter explains that chilly blood within the periphery is distributed again to the guts when the individual will get out of the pool and begins to stroll round, reducing the core temperature additional. That’s additionally why these opponents will keep away from heat showers and can as an alternative sit rugged up within the restoration room, sipping on heat drinks.

Alongside investigating this threat of a distinction between precise to perceived temperatue, the group are additionally utilizing a blood prick of the ear lobe to see whether or not coronary heart stress proteins are elevated after the swim.

There are so many claims on social media in regards to the positives of chilly plunges and chilly water swimming however, says Dr Kate Thomas: “When you look closely…There’s not strong evidence really for many of those benefits.”

Reducing irritation, boosting metabolism, psychological well being results, the listing goes on.

There are different teams which can be trying into a few of these elements, and it is possible that there are variations between the dangers and advantages skilled by people who find themselves doing short-term chilly plunges versus longer chilly water swims, Kate says.

“And we’re definitely not experts on all of that stuff, but we’re hoping to get a little bit more information around the benefits and the risks of a sport that’s clearly becoming more popular.”

In the advantages column, the group is investigating whether or not cold-water swimming boosts the degrees of mind well being associated proteins. To do that they’ll examine protein ranges from blood samples taken from cold-water swimmers to these of indoor pool swimmers.

They will not have all of the solutions, says Jim, however they’re hoping so as to add somewhat bit extra to what we all know. “It’s an unusual environment for humans to willingly spend that much time in and we’re simply not designed for it. So, it is a responsibility to just try and get more evidence around, well, what are the risks versus benefits?”

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