How does cold water swimming help our immune system?

We often hear about cold water swimming being good for our health with its practitioners extolling the benefits to all who will listen. The question that is left open is how exactly does this work? What is the mechanism that means if we dunk ourselves into freezing cold water we become healthier? That’s what we aim to unpack today. There’s a litany of claimed benefits to cold water swimming but we will focus on three - as these can be explained clearly. There are other possible health benefits, but these three are definitely true.

1. It boosts your immune system
2. It improves your circulation
3. It reduces stress.

Immune boost

A study of young, athletic, men found that single dose cold water immersion produced a minimal immune response. The men were immersed in 14 degree water for 1 hour. It was, however, found that doing this three times a week for 6 weeks had a small, but significant, increase in the proportions of monocytes and lymphocytes as well as increases in other immune marker values. Basically, regularly going cold water swimming, and thus becoming cold water adapted, improves your immune markers. These markers are an indicator of immune system performance.

Circulation improvement

When we immerse ourselves in cold water our body reacts by trying to warm us up. The ability to regulate our own temperature is quite useful and, apparently, is trainable. When we get cold our body warms us up by increasing blood flow to the cold area. This is because our arteries and veins dilate. This means there’s more space for the blood to go. As a result more blood goes to the cold parts. This process repeated over and over improves with time - a bit like training. We train ourselves to warm more effectively. Improved circulation doesn’t only positively impact our ability to warm ourselves up though - it’s also good for healing wounds, cognitive function and heart health.

Stress reduction

There are a number of ways humans can reduce the amount of stress that we feel. Broadly speaking there are two types of stress, acute stress and chronic stress. Acute stress is the hormonal response from a surprise, like when a speeding ticket comes through the mail or when you realise you have a deadline that you’ve not done the work for. Chronic stress is the kind of stress that builds up over time, for example if you work in a hospital over the winter months and it’s just slightly too busy to be manageable. When you have a stressful experience, the body responds by releasing adrenaline and cortisol. Cold water swimming also causes these hormones to be released. By doing this in a way we can control, regularly, over time we become better accustomed to dealing with other sources of stress in our life. By exposing ourselves to stress, we become better at dealing with it. Cold water swimming is actually good for our health! It’s not a fad and there are legitimate health benefits to doing so. When you go off for a dip it’s important to keep warm enough - if you’re just starting out go in a Yonda wetsuit at first and work down to skins. If you are experienced and go in skins, keep your head warm with a Yonda bobble hat and get changed after in a warm changing robe.