Have you ever wondered why it seems like people are getting sick more than they used to? I mean this in the most general terms possible. Has it ever occurred to you that we hear about more and more people coming down with things like autoimmune diseases than ever before? Have you ever wondered why?

In grossly simple terms, think about the systems of our body like a muscle. Without challenge or stress, they tend to atrophy, or weaken. For example, if you lived your whole life in a bubble, sealed away from your environment, the second you decided to step out and walk around downtown Indianapolis you would become deathly ill. This is because the body’s immune system needs small, controlled exposures to various pathogens in order to build the defense mechanisms to protect you in the future. The concept is very simple and applies to all biological systems. Natural selection – only the strongest survive and get the privilege of passing on their DNA.

We live in a “nerfed-up world” as Joe Rogan likes to put it. The conveniences of modern society are beneficial for painfully obvious reasons. No one wants to suffer the Midwest in July without air conditioning. Over time, this absence of challenge in our everyday lives decreases our ability to deal with stressors. We’ve become soft as a species. Now, I’m not advocating you ditch your AC and heat in the name of primitive living. You can have the best of both worlds by adding a little thing called HORMETIC STRESS into your life.


Hormetic Stress(noun): a controlled exposure to a beneficial stressor, which elicits a response in the body that is FAR in excess of what is necessary to deal with an otherwise non-damaging insult. This leads to a massive gain in the resiliency of our body systems on a physiological level.
One of the easiest and most researched methods of stress adaptation is through the use of sauna (heat stress) and whole-body cryotherapy (cold stress). There has been a lot of hype and misconception about the benefits of heat stress and cold stress adaptation, so let’s see what the science has to say about it:


Increased Growth Hormone

Two one-hour sauna sessions a day at 80°C (176°F) for 7 days was shown to increase growth hormone by16-fold on the third day. That equates to a 16x faster recovery and improved new muscle tissue synthesis.

Increased Insulin Sensitivity

30 minutes, three times a week for twelve weeks. This resulted in a 31% decrease in insulin levelsand a significant reduction in blood glucose levels, suggesting re-sensitization to insulin. For the Type II diabetes, or insulin-resistant diabetic population, increasing the body’s sensitivity to insulin helps to fight and may even potentially aid in the reversal of this condition. As one of the leading causes of mortality in the US, that’s big news!


Endurance Athletes

Regular sauna use has been shown to lead to a 40-50% reduction in glycogen useduring endurance activity. Think of this like a 40-50% increase in efficiency for the same amount of fuel. This is a huge leap in physiological performance. It’s the equivalent of your car going from 18 miles/gallon to 25-27 mpg!  One study in particular demonstrated that a 30 minute sauna session post-workout for 3 weeks resulted in a 32% increase in running time before exhaustion set in.

All-cause Mortality

A study was recently published in which the long-term benefits of habitual sauna users were evaluated and the results were staggering. Long term sauna users were shown to demonstrate a 40% decreased risk in all-cause mortality. All-cause mortality is an umbrella term to describe the main diseases that kill humans; cancer, cardiovascular disease, diabetes and Alzheimer’s disease. All of the subjects studied demonstrated a 40% decreased risk across the board for these diseases. This is HUGE. Think of sauna use and longevity like this – the sauna is forcing your body into “survival mode”, where the faulty or poorly performing cells are killed off and replaced by new, healthy tissue. Out with the old, in with the new.


Decreased Inflammation

It has been demonstrated that if your blood is taken before and immediately after a single whole body cryotherapy treatment, you would see an across the board decrease in almost all pro-inflammatory biomarkers. This is significant because systemic inflammation, or the inflammatory molecules that circulate in your blood are great in small doses and for a short time to heal up something like a sprained ankle. However, when they stick around too long, they fuel just about every disease process in the human body. We rack up chronic inflammation due to increased cortisol and stress, poor diet, lack of sleep, environmental toxins, etc. The less inflammation you have, the healthier you are and the longer you are likely to live a pain and disease-free existence.


Increased Norepinephrine(aka Noradrenaline)

3 minutes of whole body exposure to at least -193⁰F activates thermal receptors in your skin that trigger a 300-400% surge in Norepinephrine. This spike in Norepinephrine is one of the main drivers of cryotherapy benefits. This highly versatile neurohormone is responsible for maintaining focus, vigilance, attention and mood. Increasing the amount of circulating Norepinephrine not only helps to combat inflammation, but also the symptoms of chronic stress, ADHD, Type II Diabetes, Parkinson’s Disease, Fibromyalgia, Psoriasis, Dysautonomia, Rheumatoid Arthritis, anxiety and depression.

Increased Fat Metabolism

When the body is rapidly cooled, your body kicks into high-gear to maintain your core body temperature. Initially and for a short time, the process of shivering (rapid contraction of muscle tissue) is adequate to prevent an unsafe drop in core body temperature. However repeat exposure to cold stress forces the body vaporize stored body fatinstead of shivering to prevent a drop in core body temperature. Fat is the richest source of energy we have. That’s why we’re so good at storing it!  Repeat cold exposure triggers a complex biochemical pathway that breaks down this stored body fat. This produces energy, water and HEAT. This mechanism is a very efficient way to keep the core body temperature consistent when our environment becomes too cold for our liking. Improving your body composition just so happens to be a welcomed side-effect.


The take-home message is simple. We are all born into these miraculously versatile vehicles that are capable of handling almost anything we throw their way. They thrive when forced to adapt to our environment and tend to atrophy, or weaken over time in the absence of challenge. Over time, the weakening of these vital systems in the body leaves it vulnerable to disease, pain and premature aging. Hormetic, or beneficial stressors are an essential part of life’s fundamental equation. Don’t strive to simply survive…strive to thrive.


Content provided by Dr. Tyler Crooks