Pushing Your Limits: How Effective Are Cold Showers?

I’ve always wondered about the effectiveness of cold showers and ice baths. Many people talk about how effective they are for boosting your immune system, improving circulation through the body, increasing your alertness and energy for the day, and also enhancing your mood, and relieving stress. However, just as much as I see people advocating for it, I see 3 more people talking about how it’s just a waste of time for you to be uncomfortable and potentially even seriously hurt yourself, whether it be from Hypothermia or the shock that hits when you first feel the ice water hit your skin. I’ve tried cold showers and early morning swims before (not ice baths though), and have had some opinions on it, but I have never done the deep dive to understand whether it actually helps or not. I hope to figure that out today.

From Healthline’s medical expert view, cold therapy of any kind is the use of cold water, around 15°C (59°F), that is used to treat health conditions or stimulate health benefits. (Source) The bottom line is that cold therapy has the following pros and cons, but let’s dive into them.

Something to understand before delving into the actual results of whether cold plunges are effective or not, is our body’s natural response to cold exposure. There are four main acute effects of cold exposure. (Espeland et al (1)). (This paper by Espeland et al is a great general review source. If there are specifics that you are curious about, I would take a look at them and the references they bring up. Or just comment below with your questions!)

1. Vasoconstriction (reducing blood flow) in the skin to decrease heat loss and Vasodilation (increasing blood flow) in the muscular coating of AVAs (the connections between arteries and veins).
2. Shivering Thermogenesis (shivering to increase the heat produced, increases metabolism).
3. Non-Shivering Thermogenesis (increase of brown fat to increase heat production, increases metabolism).
4. Cardiopulmonary Responses (increased rate and force of cardiac contraction to carry more oxygen to cells)

From these four responses, you can start to understand already what the reason for many of the pros and cons are. I would guess that the shock and increased work your body needs to put in improves things like metabolism, as it burns more calories to stay warm, improves soreness or immune system function as it pumps more blood and oxygen around to regulate the body, and improves mood from the release of endorphins that your body uses at natural painkillers against the intense cold. The cons seem to mostly be the potential drawbacks if you go too far to the extreme. The question still remains though, is this a method of getting short-term, hourly or daily benefits, or do these translate to long-term benefits for the body.

To truly test the effectiveness of cold showering, Buijze et al (4) took time to run the controlled experiment and run the analysis. Their experiment consisted of 3018 participants between 18 and 65 years old. They made sure to pick participants who did not have past experiences with cold showers. They had four groups following the below procedure:

Group 1: hot shower to 30 seconds cold for 30 days

Group 2: hot shower to 60 seconds cold for 30 days

Group 3: hot shower to 90 seconds cold for 30 days

Group 4 (control): no cold shower time

After the 30-day mark, they followed with 60 days of showering cold at their own discretion.

After 90 total days of study, they had the following results:

1. Only 79% of participants could even finish the study. (12% lost within 30 days, rest lost within 90 days)
2. There was a 29% reduction in sickness absence from work compared to control groups (though they did not see significant effects in actual illness days)
3. There was no statistical evidence that a longer cold shower affected the positive outcome in sickness absence.
4. At the 30 day mark, the cold shower groups all reported improved quality of life compared to the control group, but surprisingly, this effect diminished by the 90 day mark.
5. There were no reported issues from the participants due to the hot-to-cold shower.
6. Of the groups that did do cold showering, a surprising 91% said they would continue with the routine. (due to feeling of increased energy levels, commonly compared to caffeine)
7. It is concluded (and backed by compared literature) that the first 30 seconds of the shower was the most effective.

If we do make the decision to cold plunge, how should we go about it?

Time: From Daanen HA (2) and Buijze et al (4), it seems the first 30 seconds of cold exposure are the most important. After this point, the longer-term effects on your energy levels and health are pretty equal. Daanen also points out that after a few minutes, extremities start to feel cold from the lack of proper blood flow. Your body can compensate for this, but the benefits vs the risks of hypothermia are not in our favor. Though, I should not leave out that your body working to regulate your body temperature will push your metabolism, and be helpful in burning more calories, if that is your goal.

Methodology: There are various ranges of useful temperature ranges reported, usually between 40 – 60°F. The claim is that the colder you go, the less time you need to feel the benefits, but also the more careful you need to be to not hurt yourself. The main goal is just to put your body in a cold enough environment that you feel uncomfortable. This shock and stress (hermetic) on your body will trigger all the effects you are looking for. In terms of safety, Shattock et al (3) spent time studying the different ways people faced fatal consequences in cold exposure therapies. The main conclusion came that holding one’s breath engages a ‘diving response’, which leads to potential hyperventilation, inhibition of some respiratory neurons, and redirection of blood to some of your vital organs. Steady, calm breathing is key for the best results.

Personally, I have done cold showers quite frequently, though not every day. I have always felt that my energy levels in the morning are significantly higher and the willpower to get my work done and not be as distracted on my phone or other things is lessened. Having said that, I did not see any change in my long-term ability to accomplish goals or improve my health. This seems to match up well with the 3000 participants in Buijze et al’s (4) study. From results mentioned above, I think cold exposure is worth exploring as a way to give you energy for the day and improve your discipline to do uncomfortable things. If you are expecting this to solve some underlying health issue, I think it is best to look elsewhere. NOTE: Individuals with known cardiac or pulmonary disease should not participate in cold water exposure.

Finally, based on my own experience and the results of the study, though it may not have proven physiological benefits to your body, I would highly recommend trying this out and seeing how it affects your energy and mood. I have had very positive results on that side, which in turn has improved my overall productivity during the day.

If you decide to try this, first, I would recommend sticking with cold showers as it is the free option, but I have heard and read great things about cold plunges as well. From my research, these seem to be the best deals for dedicated cold plungers:

1. BINYUAN Ice Bath Tub: Cheaper setup, but requires you to put ice in yourself. (Or just leave it outside overnight and jump in it in the morning.
2. CalmMax Oval Ice Bath Tub: Larger tub size, better insulation (also used for hot baths as well) and easier to pack up and move around (portability)
3. SOLSTICE Inflatable Cold Plunge Ice Bath Tub: Much pricier option than the others, but comes with its own chiller and filters for a more controlled ice or hot bath.

Hope this article has been helpful to all of you in choosing whether cold exposure is interesting to you! Definitely leave comments and questions below from your own experiences! I would love to know your thoughts and how they compare to my experience and the literature that was mentioned. Also, comment and let me know what other areas of interest are worth exploring and I’d love to write a piece on it!