There is a lot of hype about cold water dipping these days, with potential impacts ranging from mental health benefits through to improved metabolism.
As someone who grew up with the Finnish culture of sauna and lake swimming, with a bit of ice dipping thrown in for good measure, I have long understood the feeling of well-being that you get from this type of activity. Since moving to the mountains, I have embraced the challenge of cold water dipping without a sauna in some pretty stunning locations, and I have been interested in understanding a little more of the science behind the benefits.
In a recent edition of the HubermanLab podcast (see below for link), the Danish expert on cold exposure, Dr Susanna Soberg, discussed the evidence and her research focussing specifically on the metabolic effects. She discussed the impact of both cold and hot exposure (she looked at alternating cold water swim and sauna sessions in Denmark) on brown fat and its role in maintaining our core temperature.
Brown fat is different from white fat, containing mitochondria to convert glucose to heat to maintain body temperature, whereas white fat cells store fat as a future energy source. It seems that exposure to cold activates this brown fat in order to maintain our core temperature. Regular cold exposure leads to a level of adaptation, with the number of mitochondria in the brown fat cells increasing, and thus increasing our metabolic rate. This means that with regular cold exposure, we get better at warming ourselves up more quickly afterwards. In addition, it seems this cold exposure and activation of the brown fat also improves our insulin sensitivity, potentially reducing the risk of developing metabolic syndrome (and also Type 2 diabetes), with one study of middle-aged swimmers demonstrating a reduction in blood pressure, heart rate and improved insulin sensitivity after one winter season.
One interesting point raised in the discussion was the ‘ideal’ level of cold water exposure to see benefits, suggested to be about 11 minutes a week in 2-3 sessions. It seems that it is better to break up the exposure into several shorter sessions of a couple of minutes rather that one longer session, as it is the change in temperature that causes the stress response that activates the brown fat.
For those of you that don’t like the idea of getting into cold water, it also seems that other forms of cold exposure, from heading outside in a T-shirt, to sleeping in a room no warmer that 19 degrees, can also have beneficial effects on the brown fat activation. But for me, I’m heading up to the lake!
For the full discussion on the effect of cold exposure on metabolism, neurotransmitters and for ideal protocols, follow the link below.