Eustress & Hormesis - The Healthy Kind of Stress

We all recognize that stress has earned it’s name as ‘the silent killer,’ Not only is it an unpleasant emotional and physiological state, but through personal experience and ongoing scientific research, most of us have realized that many forms of chronic stress are not only unpleasant, but also toxic to our health in a multitude of ways.

However, not all stress is created equal. Beside the varieties of stress we can agree are bad for us (chronic anxiety, overthinking, trauma, activities that leave us feeling depleted, etc), there is a different kind of stress that elicits beneficial effects, known as eustress.

eustress / noun / yü-stres /

Definition of eustress

a positive form of stress having a beneficial effect on health, motivation, performance, and emotional well-being

Eustress is a concept that represents the milder, often more deliberate and controlled forms of stress our minds and bodies are exposed to, which create some degree of discomfort, but have a net positive effect on our well-being. It is the kind of stress that motivates and energizes us, and helps us to perform at our best.

This physiological phenomenon is closely related with another term called hormesis, and there are several pathways to achieve hormesis. Among the most potent, beneficial, and most convenient to access are exercise and heat and cold exposure.

hormesis / noun / hȯr-ˈmē-səs /

Definition of hormesis

a phenomenon of dose-response relationships in which something that produces harmful biological effects at moderate to high doses may produce beneficial effects at low doses

Hormesis is the term used to describe a beneficial response to a low dose of a potentially harmful substance or stressor. In other words, hormesis a situation where a small amount of something that is typically harmful can actually have a positive effect on an organism.

Image Credit: siimland.com

While scientists like neurobiologists and evolutionary biologists are still studying why and how many of the beneficial mechanisms of hormesis operate, recent scientific findings have revealed several new and exciting explanations. These reputable studies highlight some of the most prominent benefits and explain more of the biological mechanisms than previously known.

Among this wave of research is studies about the benefits of heat and cold exposure, specifically the kinds of deliberate heat and cold exposure that is more intense and dramatic than what modern humans typically experience in our day to day lives.

For thousands of years, humans have been exposing themselves to cold water (eg. natural bodies of water in nature, cold showers and pools and tubs of various sorts in our modern world), as well as warm rooms (eg. Scandinavian saunas and Native American sweat lodges) and bodies of water (eg. hot springs in the wilderness, Eastern European and Japanese bath houses, and hot tubs in our modern world).

And while many respectable, long-standing cultures with rich traditions of wisdom, physical vigor, and impressive vitality have sworn by these modalities for generations, it wasn’t until relatively recently that modern humans began to have rigorous and reliable scientific findings to verify these claims.

Fortunately, there has been a Renaissance of health science research in just the past decade that has included several of the most thorough and robust findings about the benefits of specific forms of hormetic stressors, such as cold and heat exposure, as well as exercise and other forms of human movement.

Most of our ancestors didn’t have the modern luxuries of climate control like central heating, electric furnaces, and air conditioned homes and vehicles. As a result, they lived with the burdens that most animals on Earth have evolved to live with: severe weather, dramatic heat and cold, and a lack of reliable shelter and optimal protection from these environmental fluctuations of nature.

In capitalizing on these tools for maximal comfort, we have given up the powerful health-protective mechanisms that these evolutionary-evolved environmental responses offer.

While there are many wonderful comforts that come with these technologies that help us evade the wrath of Earth's extreme elements and fluctuating climates, the convenience of these modern tools comes with a cost that is still hidden to most of modern society.

To put it simply, once modern humans (especially in the developed world, but increasing in the developing world as well), outsourced many of the adaptive mechanisms that our biological ancestors not only adapted to, but evolved to benefit from, we began to miss out on some of the beautiful biological responses we developed as a species over millennia to not only combat, but also benefit from extreme temperatures.

We as a modern society have now reached a point in scientific understanding that illustrates the wide range of benefits of exposing ourselves to the constantly changing tides of nature. At the same time, we have only increased our ability to easily, efficiently, and affordably eliminate the need to expose ourselves to the more dangerous aspects of the extreme environments of our ancestors.

With both sides of this coin in mind, it seems the most wise solution is to utilize our opportunities, whether in nature or through technologically enhanced tools like saunas, cryotherapy, and cold plunges, to tap into the vast benefits that our biology responds so positively to.

Simultaneously, we can appreciate and enjoy the privilege that the comforts of our modern world offer for times when we need or want comfort, like the majestic experience of sitting by a fireplace on a cold winter evening (which is often even more appreciated following a dip in a cold plunge or a cold lake), or the good fortune of not facing severe or illness or death due to extreme weather.