A couple of weeks ago, inspired by my friend Dee, I jumped in the ocean and did my very first cold water swim. Outside of the odd January 1st Polar Bear swim, I don’t typically swim in the outdoors between about October and May. Because…it’s cold! As I write this it’s December 1st. The average ambient temperature this time of year hovers between 0-8 degrees Celsius (31-48F), and the water temperature range is typically 7.6-9.9 degrees Celsius (46.6-48.9F) this time of year. Yeah. We’ll call that cool.

So why on earth would Polar Bear Dip on a random Monday in November?!

Well, first off, if you’ve been following me for a while you likely know I like to challenge my perceived limits. I mostly do this because I like to show myself I’m capable of doing hard things. It reminds me that I’m capable, resilient and kinda badass. And that “edge” serves me day to day when I’m faced with the real tough stuff.

And let’s be honest, this year has been full of “real tough stuff.” And I don’t know about you, but I could use a reminder that I’m capable, resilient and kinda badass.

So yeah, I went for it.

What I wasn’t expecting from cold water swimming…

…was to LOVE it. As soon as I got out of the water I told Dee, “that was amazing, I’m in for EVERY Monday! What a way to start the week!”

But here’s what was even more unexpected to me….

I felt truly exhilarated and alive for the whole day after the dip. I felt an elevation in my mood and a calming of my ever-present anxiety. You guys, it was kind of a big deal. And also, whoa, what the heck?!

So I did it again on Tuesday. Then on Wednesday, and Thursday. And now it’s more than 2 weeks later and I’m still dipping daily.

Some days it’s solo. Some days it’s with friends I’ve inspired to say YES. But I’ve gone. And every single time it’s felt amazing.

I’ve noticed that my big toe that I broke back in August and still bugs me, is bugging me way less. And I’ve noticed my mood is generally more even keeled and I feel calmer, less reactive. I’m also sleeping like a log and waking up before my alarm (which should be noted goes off at 5:40am). I KNOW!

Even if it’s “all in my head” these benefits are worth the 20-minutes of my day that this ritual takes me – including driving time to the beach!

The inner nerd in me started to get curious. Why is this making me feel so awesome?! Is there some science to this?

Turns out there is. Be still my geeky heart!

Here’s what I found. There are considerable evidence-based health benefits to “cold water immersion” or “cold water therapy.”

The research varies based on the temperature of the water and the duration of the time in the water, but here are some of the reported evidence-based health benefits that I found intriguing:

  • decreased muscle soreness
  • reduction in inflammation
  • decreased symptoms of depression and other negative mood states
  • improved focus
  • stimulation of your immune system
  • boosted metabolism
  • reduction of pain
  • reduced fatigue
  • improved sleep
  • increase in HDL cholesterol/ decrease in LDL cholestorol

I don’t know about you, but even if I get one of those benefits, and I continue to enjoy it, I will keep doing it! Even for the potential of boosting my immune system alone!

Anecdotally, because cold water immersion also triggers a stress response, and the resolution of the stress response, I also wonder if it could be yet another way to complete the Stress Response Cycle and prevent Burnout. More on that on this blog.

How does immersing your body in cold water….do ALL that!?

The physiologic cascade that explains how cold water immersion results in these benefits is not a short answer. Longer than this blog can fulfill, without totally boring the snot out of most readers. That said, if you’re super curious, scroll down for a link to an academic review paper that goes into all the geeky awesome detail on each benefit and some of the theoretical physiologic findings for each.

Regardless of your desire to understand just how the physiology explains the benefits listed, I do think a basic understanding around what is happening in your body during cold water immersion is helpful.

So, what actually happens when we immerse our body in cold water?

Your body’s job is to maintain homeostasis (aka. maintain a stable internal state), regardless of external environment. If the external environment challenges or “stresses” the internal state, there is a physiologic cascade of events that occurs to counter that “stressor.”

For example, your organ systems have an optimal operating temperature. If this optimal temperature is challenged (ie. the ambient temperature is hot or cold) the body has mechanisms to counteract that stressor and maintain the internal environment. This includes mechanisms such as sweating if you’re too hot or shivering if you’re too cold. This is all involuntary, meaning our bodies just do it (cool, right?!).

In the case of cold water immersion, you’re applying cold stress to your body, which challenges the homeostasis of body temperature. Your body responds to this cold stress in a variety of ways.

Here’s the short list of what happens:

  • Cold receptors in your skin sense that your skin has been cooled quickly. This triggers the “cold shock response”* which is an involuntary gasp or deep inhalation, followed by a period of hyperventilation (rapid breathing).
  • The cold also triggers your blood vessels and arteries to narrow. This restricts blood flow to your skin, which helps to minimize heat loss from the warm blood near the skin and maintain a normal internal or “core” temperature for the vital organs such as the heart and lungs.
  • In order to circulate blood through the constricted blood vessels, the heart has to work harder. As a result, your blood pressure and your heart rate increase.

*Note: this “cold shock response” is why it is important that you always enter cold water slowly. It should also be noted that research finds that the severity of this response decreases with exposures. As few as five 3-minute immersions in cold water can reduce these responses by 50% and that response can still be reduced by 25% 14 months later (cool, I know!).

Feeling compelled? Cool.

Before you go, some things to keep in mind:

  1. Talk to your doctor first. Cold water immersion affects your blood pressure, heart rate, and circulation, it can cause serious cardiac stress. If you have an underlying heart issue, there is significant risk.
  2. Don’t go alone, or at the very least make sure there is someone on the beach who can observe you. There is a documented decrease in cerebral (brain) blood flow during cold water immersion and it can decrease your reasoning and judgement, so make sure you stay safe!
  3. Go in slowly (don’t jump in). There will be a “gasp reflex” when you go in. Breathe slowly and deeply (inhale and exhale).
  4. Have a “get warm” plan for after. Especially if the ambient temperature is cold, there is a risk of hypothermia if you don’t take steps to warm up after. Check out my tips below!
  5. Keep it short! There isn’t any evidence that shows benefit beyond a few minutes of immersion. So keep it to a few minutes at most. Likewise, I didn’t see any additional benefits in the research regarding complete immersion. Most of the research talks about keeping the head out (with a toque on if you can!).

Some tips for the dips:

  • Warming your body up first can be helpful. A brisk walk or walk to the water will do it!
  • Don’t think, just do. I don’t dawdle. I get to the beach and go in. If I think about it I won’t go.
  • Wear a toque. Keeping your head dry and warm is helpful.
  • Wear water shoes so you don’t trip getting in or out (it also makes walking on the rocky terrain easier).
  • Go in slowly and take slow, deep breaths. I haven’t yet explored more extensive breathing strategies, but suspect this will be my next steps! There’s definitely some science to back breathing strategies and cold water immersion (thanks Wim Hoff).
  • Trust your instincts about when to get out, but also keep a sense of the time (use a timer on the beach if you’re concerned about the duration).
  • Immediately dry off (pat don’t rub, your skin will be red!) and layer up – core first (warm shirt/ jacket), then socks, then pants! I will say I often just drive home in my towel wrapped around my core and my puffer jacket!
  • Drink something warm as soon as you can. Some tea with a bit of honey can be helpful. I read somewhere that a little bit of sugar can be helpful to boost your system and re-warm.
  • I don’t shower until I’m home and I’m warm. If you’re still really cold, actively try to warm up in other ways more gradually (not a hot shower). The dramatic transition from cold to hot could cause lightheadedness.

Most importantly, have fun! If you go for it, send me a message! I’d love to hear about your experience!