Hormesis For Resilience: What It Is and How to Use It
“That which does not kill us makes us stronger.”
-Nietzsche
You have a better life than the wealthiest kings in history. You probably spend most of your time in a temperature-controlled environment, you can order (think about that word) food grown in South America to your doorstep in no time, and you can comfortably travel hundreds of miles before bedtime. You have access to advanced healthcare, machines that freeze moments in time with the click of a button, and plumbing!
So what is there to be stressed about? Turns out we’ve adapted very quickly. We complain when the temperature of a room teeters 2 degrees in either direction. Then there was that turbulence on your flight across the country (which was all but impossible to do just 100 years ago). And the Wifi dropped for a minute on my phone which is more advanced than the space shuttle that brought man to the moon.
Let’s face it, we live coddled lives and as a result, we’re slowly becoming weaker. Every new advancement reduces a little more friction in our life and protects us from perceived periods of stress.
The Principle Of Least Effort
Making our lives easier is just the way your mind is programmed. For hundreds of thousands of years, there was a survival benefit to humans expending a minimal amount of effort. Put simply, our ancestors who expended too much energy (especially during moments of food scarcity) wound up dead. Those who did the ancestral “Netflix and Chill” reserved their energy, lived, reproduced, and passed on their genes. Through evolution, our genetic code is programmed with a cognitive heuristic that dominates our life, the principle of least effort. This is where humans naturally choose the option with the minimum amount of resistance.
For most of human existence, this default switch has allowed humans to survive. However, humans have advanced society so quickly that natural selection couldn’t keep up causing an evolutionary mismatch. The good news is that we’re more comfortable than ever. The bad news is that we’re more comfortable than ever. It’s time to get uncomfortable.
What Doesn’t Kill Us
The answer to this paradox of having too little stress which causes stress is hormesis. Hormesis is a short exposure to stress that elicits an adaptive response. It’s inducing a noxious stimuli at the cellular level. Examples of hormetic stressors include lifting weights, running, sunbathing, and exposing yourself to uncomfortable temperatures.
Putting yourself through these uncomfortable scenarios enhances our well-being and develops mental and physical strength. Once we get past the obstacle of lifting up that first weight or getting into a sauna, feel-good hormones like dopamine and epinephrine give us instantaneous feelings of well-being. This exposure also takes us out of our comfort zone and makes us more resilient. But resilience isn’t a one-and-done thing. Doing it on a regular basis leads to a healthy relationship with these stressors and neurotransmitters and it keeps our hedonic setpoint at a healthy level—in the “joy” range. Doing this enough times, at our own volition, teaches our brain and body to involuntarily be happier, healthier, and to apply this fortitude to real-world stressors we can’t always anticipate.
Our ancestors’ natural life comprised of enough stressors that they rarely sought additional stressors to build resilience. Our worlds are different. We are in the fortunate position where we have to use our rational outer brain to override our instinctive primate brain to jump in that cold water and push the workout harder when our brain is telling us to stop. Taking part in these stressors pushes us beyond our boundaries and, in a phrase, makes us harder to kill.
The goal is to make it harder to kill but not just harder to kill in the moment. Fortunately, the benefits of hormesis extend beyond strength and resilience. They actually help us live longer. A 2008 study titled “Hormesis in Aging” suggests that “Single or multiple exposures to low doses of otherwise harmful agents, such as irradiation, food limitation, heat stress, hypergravity, reactive oxygen species, and other free radicals have a variety of anti-aging and longevity extending hormetic effects.” Short-term stress with long-term benefits.
Hormesis: The Sweet Spot
Hormesis is a fragile thing. Like most biology, it lives on a spectrum. Too little and we stay soft. Too much and we creep into unhealthy territory. A lack of sun leads to vitamin D deficiency (among other health issues) while too much causes sunburn or worse. Too little exercise and we’re weak. Too much and we suffer from fatigue, hormonal imbalances, and overuse injuries.
Finding the sweet spot is essential but so is mixing it up. Different stressors activate different pathways although there is a lot of overlap (even cold exposure activates heat shock proteins).
Let’s dive into these different types of hormetic stressors.
The Stressors
Get Hot (Sauna)
This is my favorite type of hormesis. I’ve always loved getting into that hot car in the summer or hopping in the hot tub. Heat just makes me happy.
The most common way to do any sort of “heat stress” is with a sauna. Sauna use has become trendy lately, in line with the explosion of research published touting its benefits. Rhonda Patrick, a biomedical scientist, provides an extremely comprehensive review of the effects and benefits of hormesis here. I’ll highlight some points:
Improved endurance
Helps maintain muscle mass
Helps detox the body of metals and chemicals
Lower risk of sudden cardiac death
Lower cholesterol levels
Lower blood pressure
Less inflammation
Less cognitive decline and risk of Alzheimer’s
Less depression (interestingly only one sauna session was needed to cause an “acute antidepressant effect” lasting 6 weeks)
Improved focus
Improved growth hormone
Less insulin resistance
Do this: Use a sauna twice a week for 15 minutes at a time. I use the HigherDOSE infrared sauna blanket (although a large multi-person sauna is on my bucket list). If you don’t have access to a sauna you can look for spas nearby.
Get Cold (Cryotherapy)
While heat and I are compadres, cold and I live in frenemy territory. I sucked at tolerating the polar bear plunges at the beach, crew practice on the frosty river, and I struggle to last long in even mildly cold pool water. Cold air temperatures is tolerable but for some reason, that cold water hits me hard.
While I never look forward to cryotherapy I always feel better doing it (except for a few times when I turned blue with some really cold soaks). I make a point to finish all of my showers with the coldest possible water for at least 4 rounds of box breathing from October to April (the water doesn’t get cold enough in the summer months). I get my whole body under the water but prioritize the neck and face which tend to induce the greatest benefits.
Just as Rhonda Patrick made a compressive list of sauna benefits, she did the same for cold exposure here. These are some highlights:
Improves glucose metabolism
Less risk of cardiometabolic disease
Improves immune system function
Produces antioxidants
Less pain and more function with arthritis
Improved mood
Less symptoms of depression
Increased mitochondrial biogenesis
Do this: At the end of each of your showers, turn the water as cold as possible and get as much of your body under the water for 1-5 minutes. You can also buy a few bags of ice and put them in the tub for a cold soak. If you’re a true masochist then buy The Ice Pod like I did. It’s the least expensive cold pool I’ve found and it doesn’t slack on durability. Get it here.
Hold Your Breath
When people hear “breath holding” (a.k.a. “apnea”) they instantly have two fears: passing out and some trauma to the heart. Since the body and brain are terrible at going even short periods without oxygen a fear of this deprivation makes total sense. On top of that, holding your breath is very uncomfortable and everyone who has had to involuntarily do it was likely in a scary situation that triggered a sympathetic response (fight, flight, freeze) and a traumatic story or two to tell.
Fortunately, in controlled situations and for short durations breath holds for the average person are safe. You should still talk to your doctor before doing it. Don’t do it for long periods if you have certain conditions like panic disorder and don’t do it if you’re pregnant.
But are there benefits? A 2021 study measured the effects of 13 free divers competing in the World and European championships. They found an increase in oxidative stress and a “significant positive correlation with heat shock proteins, total antioxidant status, and nitric oxide levels. These are “associated with beneficial cardiovascular adaptation.”
Other evidence-based benefits include:
All in all, the research is scant on supporting long periods of breath holding for positive health benefits. After treating plenty of people who were revived with CPR or had hypoxic or anoxic injuries, I’m leery of any long periods of oxygen deprivation to the brain. Depending on factors like age and the amount of time they were “out” there can be significant permanent cognitive impairments.
What seems to be more effective are short bouts of breath holds. I’m unaware of any research showing optimal breath hold times but anything longer than 90 seconds is too long in my opinion. On the other end of the spectrum, being unable to hold your breath for 20 seconds is an indicator that you are anxious and sensitive to stress. The shorter the breath hold the more anxious you likely are. Doing breath holds can improve your breath hold duration and your stress tolerance as a result.
Do this: While laying on the ground, take a slow, deep breath and time how long you can hold your breath (without passing out). Recover for 2 minutes or until your breathing pattern returns to normal. Repeat this 5 times. Do this 2-3 times a week and see your breath hold times improve. Have someone nearby so that you are safe in doing this. You can also use an apnea table as a guide but I would restrict the holds to no longer than 90 seconds. Here are other great breathwork techniques to try as well.
Important: Never practice breath holds in water. You can die from holding your breath for too long in the water. You can’t when you’re laying on the ground.
Fasting
Whoever thought eating less often would be all the rage? OMAD, 16:8, 5/2, alternate day fasting, warrior diet, eat-stop-eat. It sounds like military jargon rather than ways to just not put food in your mouth. These types of fasting have all come about in recent years and, thanks to the health benefits, they’re here to stay.
Fasting is one of those things that everyone should do. Not because it “hardens” you or punishes you for that slice of cheesecake but because it promotes metabolic flexibility. Teaching yourself to fast and managing your blood sugar fluctuations allows you to skip a meal (whether you want to or you have to) without being hangry.
Fasting is encoded in our DNA. Our ancestors would go days without food (famine) and then celebrate when they finally ran down their food (feast). Feasting often is a luxury we take for granted but we’re tipping the scales and doing it too often and in unhealthy ways. The modern-day rise in chronic diseases speaks for itself. You may not be there yet but a sign that you’re on your way is if you can’t sustain these periods of “famine.” The inability to stop eating for periods of time is a sign of poor health.
The benefits:
And don’t worry, working out in a fasted state doesn’t kill the workout.
Who should not fast: If you are pregnant or breastfeeding then keep the food coming for the baby. Don’t fast if you have a history of disordered eating, train hard more than 5 days a week, or easily react with acute stress to situations (i.e. anxiety) because, after all, fasting is a (hormetic) stressor. If you are pre-diabetic or diabetic then start with being able to minimize refined carbs and handling consistent exercise before skipping meals. If you feel weak or lightheaded then your blood sugar has probably dropped meaning you are probably not metabolically flexible. In that case, focus on addressing other lifestyle factors like nutrition, sleep, and managing stress.
Do this: Start small by eliminating any food or drink with calories (e.g. snacks) between meals then work up from there: don’t eat or drink anything for a 12-hour period (sleep time included), then work up to 16 hours by skipping a meal. Do this for a few weeks and work up to longer periods. Here is a more comprehensive breakdown of the different types of fasting and suggestions for finding the best one for you according to Marks Sisson.
Takeaway
We humans are inherently lazy thanks to a cognitive bias that was once a key feature of our survival. This laziness preserved energy, however, they didn’t become soft or weak because our ancestors were constantly exposed to stressors. We now live in the lap of luxury and we’re rarely, if ever, exposed to the stressors our ancestors experienced. As a result, we are safer but also unhealthier than ever.
In order to become healthier, we need to challenge our mind and body through hormetic stressors. Hormesis is short bouts of stress that create adaptive responses. Examples of hormesis include heat (typically sauna), cold (typically water), breath holding, and fasting. Doing any of these stressors for too little (or never) results in weakness and too much has its own suboptimal consequences. Willingly and regularly inviting pain and discomfort into your life improves your happiness, resilience, and health.
Which form of hormesis is most challenging for you? What techniques do you use to sustain the discomfort?
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