Dousing yourself in cold water might not seem like the best way to start your day, but it’s been a popular practice for centuries – ancient Romans used ‘frigidarium baths’, while the Norse cracked open icy lakes for the occasional winter swim – and now tech entrepreneurs and biohackers are diving in. Should you take the plunge? Increasing evidence that it comes with a whole host of benefits suggests it’s worth a try.
First among the potential upsides, there’s the ‘mammalian diving response,’ which you’ve already encountered if you’ve ever jumped into a cold lake or swimming pool – it’s the effect that when your body slows your heart rate after you are submerged in cold water as a way to conserve oxygen. Advocates argue that it also ‘resets’ your emotions as your body shifts into focusing on surviving underwater, increasing activity from your parasympathetic nervous system and downshifting your fight-or-flight reflex. This is why Silicon Valley types do it: when stretch goals and overflowing inboxes are causing mounting stress, the theory goes, even pressing an ice-pack against your face can turn down your stress levels.
And fat loss? The key word here is thermogenesis: when you soak yourself in cold water or use ice packs to lower your body temperature, the theory goes, your body is forced to create heat by burning fat, while also increasing its production of testosterone and growth hormone, reducing inflammation and increasing your insulin sensitivity. Hardcore advocates also claim improved thyroid function and ‘nerve toning’, but the science behind them isn’t quite so convincing.
Finally, it doesn’t have to be too much of an ordeal: biohackers might be sitting in bins of ice or covering their faces with cold-packs in the office, but it’s likely you can get most of the positives with much less pain. The entry-level version? Crank the water to cold for the last thirty seconds of your shower – or dunk your face in icy water for a few seconds in the morning. Our cold take? It’s got to be worth a try.