With the slow but sure reopening of gyms and body oriented therapy and rehabilitative modalities such as physiotherapy, massage, and sauna, focusing on ways we can bring these activities into our lives will be useful for cultivating some serious resilience against stress, and give us a chance to manifest feelings of control over our lives. This week’s post will explore some of the scientific findings surrounding sauna and how it can be used to create lasting resilience across the lifespan while drastically improving quality of life.

One of my favourite ways to wind down after a long day just so happens to also be a potent and reliable source of feel good neurotransmitters and hormones, positive adaptations across numerous systems of the body, and can actually replace or operate as a different form of exercise… yeah I said it, you can actually workout while hanging out in your underwear! So let’s dive in.

The sauna for many is an all encompassing, holistic activity which can range from a relaxing session with some friends, to a 20 minute solo expedition into some of the most intense “exercise” one can do at home or local gym/bathhouse. Before I get into how I enjoy my sauna sessions the most, I’d like to consolidate some of the research findings that stand out to me.

Are you over feeling tight, tired, and sore all the time?

Research has found saunas to benefit many systems of the body including the endocrine, blood and vascular, cognitive, immune, fascial and musculoskeletal systems. Starting at the cellular level, saunas have been shown to induce proteins called Heat Shock Proteins (HSPs). When our body temperature jumps up like it does in the sauna or when we have a fever, the walls of our cells begin to weaken and start to leak, leading to an increase in permeability. Think of a busy night club without any bouncers controlling the rate of people coming and going – it can get chaotic quick. As our cell walls start to leak, ions like sodium and potassium start to enter and exit at untypical rates, leading to chaos in the form of poorly constructed proteins which then start to clog up the inside of the cell. The job of the Heat Shock Proteins is to repair and chaperone these aggregated proteins out of the cell. Strategic sauna use, which research seems to suggest is around 20 minutes at 120C, can help upregulate the genetic pathways that create HSPs and thus improves your cell’s ability to unfold and/or remove aggregated proteins. This is highly relevant stuff, especially in research and clinical work with degenerative disorders due to genetically protective qualities.

So far, so cool huh? Zoom out a little farther and start to look at larger systems like the vascular system. In the sauna, much like exercise, our core temperature is increased, which allows the veins and arteries to relax and dilate, oxygen is delivered to tissues quicker, and our heart rate increases, pushing more blood to further and smaller places. With this modification in blood dynamics, we see a significant increase of blood flow to the brain. Increases in cerebral blood flow have been shown time and time again to lead to favourable outcomes like improved cognitive performance, reduction in all cause mortality, and reduced occurrence of both acute and chronic cerebrovascular events like stroke and dementia. Blood flow to the brain is good…so long as the blood is kept inside those vascular highways.

Sauna is also correlated with substantially reduced risk of Sudden Cardiac Arrest. Interestingly, sauna and exercise is more strongly correlated with positive outcomes than either of the modalities on their own, meaning that exercise and sauna use combined do more for your health than just exercise or just sauna use alone. In fact, research suggests that in regards to heart disease, ischemia, and coronary heart disease, sauna tends to be safer than exercise. Some of the proposed potential mechanisms of these vascular effects are reduced arterial stiffness, decreases in inflammation and oxidative stress, stability of CNS, positive changes in circulating lipid profiles and other risk markers, and lowering of systemic blood pressure following sauna sessions. Additionally, a longitudinal study showed that frequent sauna-ers (4-7x/w) showed reduced levels of systemic inflammation.

If we zoom out just a little farther and begin to look at the musculoskeletal system, we see even more interesting outcomes. A study by Heinonen, and Laukkanen (2017) showed sauna use to also increase blood flow through the musculoskeletal, bone marrow, and fascia systems. By frequently increasing blood flow to these systems, our body has an easier time communicating with and delivering useful nutrients whilst removing toxins and biological waste. The great Dr. Kelly Starrett words it best, “bring in the groceries and take out the garbage”. The study also identified some interesting body temperature adaptations:

• Lowered average body temp which correlates with increased parasympathetic activity

• Increased tolerance for higher temperatures; heightened mechanocellular “roof” or tolerable levels of heat translates to positive effects on protein folding.

Heat stress also improves skeletal muscle contraction. And get this - although the mechanism is not known, heat adaptations have shown to induce progenitor stem cells which is certainly a potential site for therapeutic application. If you’ve read anything about stem cells, I trust you’re feeling an extra urge to jump into your closest sauna. The authors of the study mention that although there are no skeletal muscle contractions in sauna that would account for the increase in RR, HR, and BP, the increased metabolic demand can account for these changes. Skin blood flow also increases; sweating leads to a balancing of bodily fluids during and after sauna. They also found impressive positive effects on cholesterol and lipid profiles, boosts in immune function; even increases antioxidant capacity because heat shock proteins boost antioxidative enzyme activity.

Now is better than ever before!

Although the research remains relatively unclear in regards to Covid, mostly due to the recency of this pandemic, the research suggests that 4-7 solo sauna sessions per week may help by strengthening the immune system to better fight off and prevent the spread of viruses. By adding this practice into your daily routine (if you have access to a somewhat private sauna), you will be improving many systems that are highly relevant in combating sickness and improving your capacity to handle larger physiological loads which I’m sure many of us are feeling these days. I believe its an important activity to have because there are so few things in our lives, besides the essentials like exercise and a proper diet, that can manifest so many benefits across our biological and psychological systems with such a small investment. I mean… go sweat in your underwear, FOR HEALTH!

See you guys next week