Hormesis: How Discomfort Makes You Stronger

Stress is a complicated beast. It’s the chaos caused by a bad day at work, sure, but it’s also prompted by what we eat, how we move and our environment. It can be good for us by stimulating resilience and growth and, conversely, too much of it can break us.

Stress can be acute (fleeting), episodically acute or chronic (persistent) and generally falls into three categories: emotional stress (what we think or feel), chemical stress (what we put in our bodies) and physical stress (what we do to our bodies).

Any of the emboldened three if left unmanaged will impact how we handle life… and how life handles us.

This is where the topic of today’s musing comes in: hormesis. It’s the scientific principle behind stress being beneficial: the positive outcomes of eustress rather than the negative distress.

As with everything in life, it comes down to balance. Too little stress provides no benefit and too much dropkicks us into burnout, injury or illness. It’s the Goldilocks principle for life: we need stress that’s just right.

Hormesis is the biological equivalent of “what doesn’t kill you makes you stronger.” The benefits are found in the sweet spot where we’re challenged but not overtaxed. This is illustrated by the hormetic curve (pictured below).

As outlined in our multiple pieces on allostatic load, we must stimulate our body to encourage improved performance without asking too much of ourselves.

Hormesis is how we evolved as a species. It’s why discomfort can lead to growth—but only when it’s managed. So, if we're looking to thrive, it’s not about doing more or pushing harder. It’s about finding the right amount of challenge to spark improvement without tipping over into distress. Too much stress and we break. Too little and we plateau.

Exercise is the easiest way to understand hormesis because it’s intuitive. We stress our muscles and cardiovascular system just enough to build strength and endurance. Then, the following session, we’re a touch fitter or stronger than before.

The thing is though, we need to keep pushing. Run 5KM at the same pace every day for years and we’ll plateau, halting progress in the process. The body adapts to the stimulus. After all, we’re evolutionarily wired to preserve energy. The key is to change things up. Run a little longer, or slow down and extend the distance. It’s all about finding what’s strenuous for you. 

As you’ll know if you’ve ever been to a fitness class, what’s hard for some is a cakewalk for someone else.

Diet’s another great example of hormesis. Every bite of food we eat, whether it’s cake or kale, creates a challenge for our body to break down, absorb and use the nutrients. The difference is whether the “stress” of digestion creates a net positive or negative effect on our health.

Antioxidants and polyphenols, found in many nutrient-rich foods, are often mild toxins produced by plants to protect themselves from pests. Consumption stimulates the body to activate protective mechanisms, like reducing inflammation, improving metabolic health or enhancing cellular repair. This is hormesis in action.

That said, sticking to the same foods can blunt the benefits. Humans are brilliant at adapting, so the stress of processing the same nutrients stops being as challenging. This is why eating a varied diet, switching between stricter diets or following a seasonal pattern of consumption, is beneficial. It keeps our system on its toes. The diversity builds a more robust gut microbiome, strengthens the immune system and challenges the body to adapt to different nutrient profiles. Ultimately, it improves performance.

Fasting is another example of harnessing the power of hormesis. It challenges the body to adapt to the temporary absence of food. But, just as we wouldn’t jump into a marathon without training, we shouldn’t suddenly forego food without training towards longer durations. It’ll kick your arse.

Doing it sensibly – say by building from 8 hours without food, to 10 hours, then 12, up to 20 – will gradually introduce the benefits of fasting without ruining our wellbeing (and our mates' who'd have to listen to our moans).

Simply put, the benefits arise by withholding energy from the body. This signals that we need to optimise our systems for survival. The full benefits are for a future musing, but the main ones include autophagy activation, mitochondrial management and sirtuin stimulation.

Another way to push and gain is to flip your fast – eat food early in the day and then fast, or do the reverse and only chomp in the afternoon. The benefits of hormesis come from changing things up.

While we’re looking for just the right amount of stress, our final example of hormesis comes from being a little hotter or colder than we’d typically choose. Contrasting temperature therapy (e.g. saunas or cold plunges) makes us stronger by exploiting the body’s responses to extreme heat and cold.

Exposure to high temperatures activates heat shock proteins, which improve cellular function and repair damaged proteins. It also dilates our blood vessels, improving circulation and oxygen delivery throughout the body, in turn this strengthens the cardiovascular system.

Unsurprisingly, cold provides a reverse response and activates cold shock proteins which promote stress adaptation. This exposure constricts blood vessels, which reduces inflammation and promotes recovery.

The goal is not to push too far. Try turning the temperature down on the shower before deciding to introduce a wild swim into a daily routine. Or hit up a hot yoga session and try not to pass out. The trick to knowing whether we’ve hit the sweet spot is to check how we feel once we're back in “normal” temperatures. The idea is to stress, then return to baseline. Hormesis, once again, is all about finding the sweet spot.

No, Ant & Dec aren’t retiring – this is the conclusion. 

With all of these behaviours, the gains in performance will come from starting small, staying consistent and building out from there. Variation is key, avoid adapting to the same routines. Go to an exercise class where they make you do stuff you dislike. Rustle up some new recipes. Give a 16:8 fasting routine a whirl.