Hormetic Stressors and Why They’re Important to Your Health

Written and medically reviewed by Rich LaFountain, PhD

Stress often gets a bad rap. That’s because when we think of stress, we typically think of chronic stress, which is the unrelenting sort associated with systemic inflammation, disease risk, and burnout. However, not all stress is bad. In fact, if it weren’t for the good stress in our lives, we’d never grow or see improvements in cognition, physical strength, or cardiorespiratory or immune function.

The key difference between good (hormetic) and bad (chronic) stress is that good stress has an end point, after which your body has an opportunity to rest and rebuild — and it’s the rebuilding that promotes resilience and longevity. Therefore, if you’re motivated to live a longer, healthier life, you should learn to manipulate stress to your advantage. Read on to learn how.

What Are Hormetic Stressors?

The term “hormetic stressor” comes from hormesis, a process in which your body and cells respond, recover, and improve after mild stress (which is caused by — you guessed it — a hormetic stressor).

There are many examples of how hormesis can work in your body. For patients suffering from milk allergies, researchers have demonstrated that regularly consuming small amounts of milk reduces the patients’ sensitivity to allergens over time. Similarly, individuals with hypertension can actually improve their resting blood pressure by engaging in low-intensity exercise, which works, somewhat counterintuitively, by slightly elevating blood pressure. In these two examples, the allergen, milk, and the exercise serve as the hormetic stressors: intentional, mild exposures to stress that produce a brief challenge, response, and recovery pattern inside our bodies.

Longevity Benefits of Hormetic Stress 

The vital distinction between a “good” hormetic stressor and a “bad” toxic stressor is the mild, intermittent nature of the former, which enables your body to recover, repair, and rejuvenate. While chronic stress accelerates biological aging, hormetic stress actually improves aging because it activates protective mechanisms all over your body that have anti-aging biological effects. 

Hormetic Stress Habits for Improving Health

If you are looking to maximize healthspan and lifespan, hormetic stress should be part of your routine. However, there is some strategy and intentionality to identifying the hormetic stressors that will most positively impact your unique biology and aging processes. Here are several research-backed habits to consider.


Exercise is the most common hormetic stress intervention, and rightly so — studies suggest it increases the odds of healthy aging by 39%. It does this through a plethora of mechanisms: Exercise enhances mitochondrial health, regulates glucose, improves cardiorespiratory function, stabilizes telomeres, reduces oxidative stress, and activates both autophagy and heat shock proteins, all of which improve your health and longevity at a cellular level. You can also induce specific benefits depending upon what type of exercise you choose. For instance, zone 2 exercise improves fat metabolism, while resistance exercise helps to increase skeletal and muscle mass.

Resistance exercise is a classic example of how hormetic stressors work. During resistance exercise, you are intentionally using mechanical force to stress and create microtears in your muscle tissue. At the end of the workout, provided you take sufficient time to rest before you exercise again, your muscle recovers and repairs itself in order to become stronger and more resistant to tearing in the future. Over time, repeating this process will cause the muscle to grow and become stronger; therefore, the mechanical force (weight) you must lift to stress and break down the muscle increases.

Research is clear that the more healthy muscle mass and strength you can accumulate in your younger years, the better your quality of life will be as you age. So if you’re thinking of adding this hormetic stressor to your routine, do it now!  


Restricting energy intake with intermittent fasting is a great way to use a hormetic stressor to improve your metabolic flexibility and regulate growth signals for health and disease protection. Routine fasts of 12 hours or more provide a hormetic stress signal that conditions your metabolism to stay flexible and maintain stable energy levels using carbohydrates or fat (as opposed to primarily carbohydrates, which is what happens when we eat around the clock). This is easily achievable by eating dinner on the earlier side or delaying breakfast — just don’t snack in between.


Heat exposure, particularly through a sauna, can mimic the longevity-boosting effects of exercise. Research demonstrates that using a sauna for 15–30 minutes one to three times per week provides a hormetic stress activation of heat shock proteins that can slow muscle atrophy, an essential part of healthy aging. The aftereffects of heat can have antidepressant effects and increase endorphin release, producing euphoria similar to a runner’s high — so some benefits of this stressor aren’t only long-term, but immediate, too!

If you don’t have easy access to a sauna, you can instead use a personal sauna suit while exercising, spend time in a hot tub, or create a heated environment (air temperature of 112 to 212 degrees Fahrenheit) using conventional, infrared, or even solar heating to experience heat stress benefits.


Cold exposure, cryotherapy, and even hot-to-cold showers have been shown to promote overall health and well-being. Routine winter swimming (or, for most of us, cold water exposure) three to four times per week has been associated with improved wellbeing and mood. In one study, 30 consecutive days of hot-to-cold showers, with cold exposure lasting only 30 to 90 seconds, improved immune function and reduced illness by 29%. So even if the thought of a frigid shower makes you shiver, just a minute of turning down the temperature could yield positive results.

In addition to the four hormetic stress tools highlighted above, there are a number of other tools that have shown early promise for improving health or extending lifespan. These include low-level radiation, low-frequency electric stimulation, mechanical vibration, and hypergravity. Given the positive results from preliminary animal studies, keep an eye out for evidence-based protocols once these hormetic stress tools have been tested on humans. 

If you chiefly view stress as something to be avoided, then you’re probably overlooking the positive impact that short-duration hormetic stress can have on your healthspan and lifespan. Routine exercise and nutrition goals are not new, but now we have the research to adjust the timing and dose for optimal health. Work in a little hot and/or cold exposure, too, and your intentional approach to stress will put you on the path to a longer, healthier life.

Rich LaFountain, PhD
Posted in Health & Science

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