Hormesis 101: Small Doses of Stress to Live Longer

Getting the right dose of sunshine is hormesis

What on earth is hormesis? And what’s it got to do with you?

Yet the concept is one that most of us use frequently – even every day!

You tell me you definitely don’t.  Ok.  Let’s see.

But have you ever done any weight lifting? Or trained for a swimming race or a hiking holiday?  What about deep breathing exercises?  Or cold water showers?  Have you gone on a diet?  Got a sun-tan? Do you do puzzles?  Have you had a vaccination?

If you’ve done any of those things, you’ve indulged in hormesis.  It’s an incredibly attractive concept that can lead to lengthening your life, keeping you fitter, healthier and more active.   

Wouldn’t you like more of all those things?

Yes.  Ok, so what is hormesis, how does it work and what can it do for you?  Let’s start with finding out what on earth it is.

Navy Seals, Poison and A Little Bit of What You Fancy

Hormesis is all about stress.  The easiest way to sum up the idea is to take the motto of the US Navy SEALS:

What doesn’t kill you makes you stronger

(It was first said by the philosopher, Nietzsche.) 

Picture of a navy seal who subscribes to hormetic training, diving in a jungle

You do something and if you survive, you’ll be stronger.

Whilst the motto isn’t exactly true in every case, you get the idea. The more you do, the more you can do.

16th-century medic, Paracelsus, came at it from the other end.  He said that everything can be poisonous to you, including all the things that we think of as being good.  

For example, we all need water.  Drink too little and get dehydrated, you can die. But if you take in too much water, you can also die. That even has a medical name – hyponatremia!

Just like the Navy Seals, Paracelsus didn’t mean that this was true in every case.  He revealed his big insight when his work ended up in the adage:

The dose is the poison

What he meant was that everything can be dangerous if you take it in the wrong dose. 

Put the ideas together and you get hormesis:  a little bit of something will make you stronger.  Too much or too little can harm you. 

(If that all sounds too posh.  Think of your grandma telling you that ‘a little bit of what you fancy does you good’.)

Two Real Life Examples of Hormesis:  

Running Yourself into the Ground

Years ago, I wanted to get fitter.  I trained and successfully ran quite a few half marathons, improving each time. As the Navy Seals said, I had definitely got stronger. I set myself the target of running a marathon.  So, I upped my training even more. 

exhausted marathon runner - too much running can depress your immune system and you'll get sick.  Some running is healthy.

I got sick. I told myself it was only a cold – and kept on running. Within a few days, the cold turned into a chest infection which stopped me doing anything at all other than staying in bed. I’d run myself into the ground.

I hadn’t got the dose right.  My body was so busy healing the stresses I’d put on it by running too many miles that it didn’t have the reserves to fight the cold I caught. 

And so despite all the hours of training I put in, I missed running the New York marathon.   Boo-hoo!

Stuffing Yourself with Chocolate

Here’s a yummy example.  Most people love eating chocolate. In particular, dark chocolate provides loads of nutrients that rapidly increase your chances of living longer.  Eat a bit of dark chocolate and it will benefit you with big doses of antioxidants.  It’s good for you.

But, eat too much of it and either you’ll be sick or, in the longer term, you’ll get heart disease and shorten your life!

Look at how the risks change according to the dose!

J Curve figure of dose of chocolate for heart health illustrating its hormetic effect.
Jacob Schor, ND, FABNO in Natural Medicine Journal

The chocolate and heart disease table above shows a great example of how you have to get the dose right. 

A big bar of chocolate tempting you to eat too much.  A small dose has a beneficial hormetic effect on your heart
So difficult to resist eating the whole bar.

In essence, hormesis is about applying something as a remedy in a dose that is the right amount to do you good.  If you exceed the right dose, it just makes matters far worse.  If you undershoot the right dose, you may lose out on the good stuff.

It’s all rather complicated though.  What then, can YOU do to get the benefits of hormesis?

9 Types of Hormesis You Can Use without a PhD In Science

1     Pushing Yourself into Exercise

Weight lifting is probably the epitome of hormesis through exercise.  You lift a weight and repeat lifting it until you tire.  As you grow stronger, you increase the weights.

TIP: you don’t have to go to a gym to do weight lifting.  Use your shopping or baked bean cans or litre bottles of water – even the hoover is a weight for you to lift!

weightlifting couple demonstrating their skills outside as a good example of a hormetic exercise.  too heavy can injure you

Nearly every type of exercise stresses your muscle fibres and slightly damages them.  During your rest or sleep, your body repairs those little tears.  You end up with stronger muscles than previously.  

And there we are: exercise delivers your hormesis. 

Try walking, running, dancing, swimming, kick-boxing – anything that gets you moving.  You’ll improve your chances of living longer and more healthily.

The Dose: do enough to give yourself a workout and then rest to allow your body to repair itself.  Start slowly and build up gradually.  Don’t forget, if you overdo it, you’ll feel sore and stiff and might damage ligaments or muscles. 

2     What Can Dietary Phytochemicals Do For You?

We benefit from eating more fruit and vegetables for better health and protection against some of the nastier diseases of old age.   But, as well as all the wonderful vitamins and minerals that they deliver, plants deliver low doses of phytochemicals.  

A bottle of poison, showing how phytochemicals kill bugs and illustrating that they could kill humans too

They sound rather ominous, don’t they? And they are: phytochemicals are chemicals which are poisonous to bugs.

They would be poisonous to humans too, if they were delivered in big doses.

Fortunately, the dose delivered via your average fruit or vegetable is low by human standards.  Instead of poisoning humans, these phytochemicals activate chemical pathways which release detoxifying enzymes and antioxidants, triggering beneficial, anti-inflammatory and antioxidant effects.

So the human response to these phytochemicals is truly hormetic.

Here are some examples which you might already be experiencing:

Green Tea: Asia has long held green tea in high esteem for its beneficial properties. The phytochemicals, such as polyphenols, that it produces, protect the tea from injuries and being eaten by bugs.  These polyphenol compounds have been associated with reduced risk of coronary artery disease in humans.

green tea has lots of phytochemicals.  They are great for your health but too  much is detrimental

The Dose: don’t drink more than about 6 cups of green tea a day.

PEITC, phenethyl isothiocyanate occurs naturally in cruciferous vegetables such as Chinese cabbage, turnips, rutabagas (swedes), watercress and radishes.  PEITC inhibits tumours and prevents the formation of cancer cells in humans.

The Dose: Too many veggies can give you gas, bloating and digestive discomfort.  Heart patients should keep it down to 2.5 cups a day if you’re on blood thinners as these veggies are full of vitamin K which clots your blood.  More than that can inhibit the absorption of iodine and cause thyroid problems too.

Curcumin, the active ingredient in turmeric, has many beneficial effects on humans, amongst them the triggering of the defence mechanisms inside our cells and the release of detoxifying, anti-inflammatory enzymes. 

The Dose: Keep it to less than 450 mg.  Higher than that may cause headache and nausea.

Although more research is needed, it seems that phytochemicals can be particularly beneficial for the nervous system and for protection against Alzheimer’s and Parkinson’s diseases. Researchers are looking at supplementation of the active ingredients in foods such as blueberries and turmeric to help protect sufferers against those diseases. 

The Dose: make the majority of your food a wide variety of vegetables of all different colours.  Eat smaller amounts of fruit and a wide variety of other foods and spices too.

3     Food, Dieting and Fasting

Between eating too much of the wrong things (obesity) and eating too little of the right things (starvation), there is a balance to be struck.  Why?  Because how you eat or don’t eat, is subject to hormetic effects.

Down the centuries, doctors have used fasting to heal people from illnesses and to keep them healthy.   And some people fast for spiritual reasons too.  

Going without food stresses your system and triggers different reactions such as autophagy.  This means that a chemical pathway is activated which cleans up your system and recycles damaged bits of cells by turning them into energy to create new cells. 

Vector of intermittent fasting, mug, alarm clock, illustrating that you need to calibrate fasting for best hormetic effect
Fasting is a great example of hormesis.

The Dose: Some advocate extreme fasting such as for 48 hours or much longer. These days, you’ll find it talked about in terms of 5:2 (five days of eating what you want and two days of eating sparsely). 

Another method of “fasting” or “calorie restriction” is to eat only in a restricted window of time each day.  So it might be 16:8 (fast for 16 hours and eat moderately within the 8-hour window).  Or, you can do 5 days normal eating and one or two days of 500 – 800 calories: the 5:2 method.

Calorie restriction helps you live longer!

4     Deep Breathing and Hypoxia 

We all need to breathe and oxygen is vital to keep us alive and active.  Do we get enough oxygen?  Perhaps not if we’re breathing shallowly as we hunch over our computers and phones.

Deep breathing techniques have also figured down the centuries as a means of making you healthier and longer-lived. Whether the deep breathing is done from ancient yoga practices, the Buteyko or Wim Hof methods,  it stimulates the parasympathetic nervous system and reduces stress.  Don’t over do it – you might get light headed and faint.

Breathing deeply is good for helping you relax.  Too much makes you feel spaced out.

The second part of these exercises consists of holding your breath.  That’s hypoxia; when you are deprived of oxygen.  Too much time without oxygen will damage all your systems, particularly your brain.

But, the effect of a bit of hypoxia is to stimulate the production of red blood cells so that more oxygen can be carried around your body.  Your body starts building more mitochondria too to protect against future lack of oxygen.  So you feel as though you have more energy. 

(If you’re going to climb mountains, the side effects help you to acclimatise to high altitudes.) 

Your body sees holding your breath as stress – something is going to attack you! So it activates its fight and flight defence systems and increases the production of white blood cells.  

warriors marching to fight are protected by warrior white cells to deal with injury quickly

When you get struck down by the arrows of the marauding hordes, you’ve got lots of your warrior white cells to deal with an injury or bug quickly.

And that reduces inflammation. Less inflammation means less ageing.

Whilst the immediate effect of the lack of oxygen increases your cortisol to gear you up for the fight or flight, it gradually drops and then stays lower all day, so that the overall effect is less stress on the body.

The Dose: Highly individual.  Consult your trainer.  Please don’t stop breathing for lengthy periods and never do so in baths, swimming pools or showers or if you have a medical condition.

5     Saunas to Entice You to Longer Life

If you’ve never indulged in a sauna, you’re in for a treat.  The Finns invented saunas to keep warm in the winter but quickly realised it not only makes you feel amazing, but it’s really good for your health. 

High heat increases oxidative stress and, of course, ultimately too much heat can kill you through heatstroke and dehydration.  But in moderate doses, extreme heat has highly beneficial effects on general and cardiovascular health and mortality as well as reducing the risks of dementia and Alzheimer’s disease.

High heat activates heat shock proteins.  The function of these proteins is to protect cells against the heat and to repair any damage already suffered.

Woman controlling the right dose of heat to improve her health from heat of sauna

The Dose:  start off with a few minutes in the heat.  Work up to about 20 minutes.  Make sure you drink plenty of water both before and after the sauna so that you don’t get dehydrated. 

 Use a sauna every few days if you can.

6     Cold Showers, Plunge Pools and Ice-Baths

If your body is subjected to extreme cold, it triggers a similar process to heat, but with cold shock proteins.  These trigger the production of antioxidants.  Potentially, cold water stress can protect you against the ageing effects of inflammation, trigger anti-tumour immunity and increase the survival rates from some cancers. 

Wading in a freezing mountain stream gives you a dose of cold for health benefits

Here’s me, trying out wading in a glacial mountain stream. It hurts when it’s really cold!

The Dose: In my view, cold therapy is definitely something to work up to.  Try cold showers just on your legs to begin with and move up your body.  Train yourself to enjoy a cold shower for up to say 5 minutes.  Take at least a month to get that far.

I started with cold showers and moved on to paddling up to my knees in cold mountain streams in winter – much to my husband’s embarrassment. You can then maybe move onto ice baths.   

7     Blowing Hot and Cold

Or you can try hot and cold therapy to gain the advantage of both.  For example, jumping into a cold plunge pool after a hot sauna or a steam bath. 

The Dose: again, I recommend SLOWLY working up to both the maximum heat dose and a sudden plunge into cold water. Try a cool shower to begin with and gradually turn the water temperature down. 

Stick your feet into a bath with ice in it or sit on the edge of the plunge pool (or a cold mountain stream, lake, river or the sea if you live near!).  Work up to putting your whole body underwater over as many sessions as it takes.  

Over time your body does adapt and you get to look forward to the contrast in temperatures.  I am now able to jump into the sea from my boat without screaming and procrastinating.

There is no doubt that when you’ve got used to either hot, cold or both, the therapy makes you feel amazingly wonderful. 

8     Stressed Out of Your Comfort Zone

Stress is used as a coverall term for so many things that cause some of the problems that we have to deal with every day, e.g. the environmental stress of living in polluted cities. 

But it is most often used in the context of mental stress: e.g. worrying about your mortgage, tearing your hair out over your relationships or your job. 

Excess stress can lead to illness, depression, breakdown and even suicide.  That’s serious and can make you really ill.  (Go and see a doctor if you feel that bad.)

But a certain amount of mental stress can be highly beneficial to your brain.  You learn to deal with it and get better at handling it.  In the process, your brain is stimulated into growing more cognitive reserves which can assist in preventing mental decline as you age.

Man and dog getting a dose of  hormesis from jumping out of a plane

If it makes you feel better, take your dog with you for comfort.

The Dose:  It’s impossible to generalise – we’re all different.  But a general way of looking at it is to allow yourself to be pushed ‘out of your comfort zone’.  It’s something that is rather difficult for you, but not impossible and not overwhelmingly frightening. 

You don’t have to jump out of an aeroplane.  For example, do something that you find a bit scary, such as making a speech or taking an exam.  

I’m currently plucking up the courage to start a podcast or do a live video. Both of these are well out of my comfort zone. However, I have friends who are complete naturals at doing such things and find it fun!

9     You Already Know about the Hormetic Effects of Sunshine

Whether you know it or not, you probably are already well aware of the hormetic effects of sunshine.  People who don’t get enough of it suffer from Vitamin D deficiencies.  Seasonal affective disorder is especially likely if you live in Northern countries.  

People who get too much sunlight get sunburnt!  Alternatively, they might get skin cancer. 

Too much sunshine can be very bad for you. Best to cover up

But getting out into nature and getting a dose of sunlight is very good for us in many ways.  It makes us more alert as it turns off our melatonin production, helps us sleep better, improves our mood, lowers our blood pressure and strengthens the immune system.  Humans were designed to run around outside and it does great things for you to get exposure to sunlight.

The Dose: we all need a daily dose, whatever the weather.  At least 20 minutes, preferably in the morning.  If you live in a place where the sun is very strong, then be careful to use sunscreen to protect your skin from cancer and ageing.  Be especially cautious if you have fair skin.  But don’t think you’re immune if you have dark skin.

What’s the Right Dose For You To Reap the Benefits of Hormesis?

Because everyone is individual, it’s really hard to generalise what a dose for a particular activity should be.  My example of training for a marathon shows that it’s really easy to get the doses wrong. 

I’ve given you suggested doses where I have found sensible suggestions, but you are the best judge of what you can handle.  The ideal is to push yourself a little bit, but not so much as to trigger the adverse effects.

A simple method is to choose one activity and start with baby steps.  You probably already eat vegetables and fruit, but how about increasing the amount of the super plant foods you eat, such as blueberries, avocados or greens?  Do it gradually. 

Illustrating that we have a choice as to what to dose ourselves up with.

Enlist specialist help whenever you need to.  For example, if you’re doing more exercise, get a trainer to guide you through suitable exercise routines.

It’s always better to get medical advice if you have any doubts about starting new activities that are likely to stress you somewhat – and essential if you already have any medical conditions.  Particularly be sure to get medical advice if you have any kind of autoimmune disease. You don’t want to make matters worse!

The Bountiful Benefits of Hormesis

Your body is always trying to keep you in your best shape.  It has many, many checks and balances within it to fix all the things you do every day that damage it. 

But imagine giving yourself a helping hand along the way to increase the effectiveness of those checks and balances.  Imagine stressing yourself just a bit most days of the week.  Maybe you’re learning a new skill.  Or maybe you’ve taken yourself out into the daylight more, rather than confining yourself in an airconditioned building.   

Feel the additional resilience that you’ve gained, how you’ve improved your mood.  Feel the pride of being able to walk your 10,000 steps a day, when a while ago, you could only do 2-3,000.  

You’ve got more energy and feel more alive.  You can do more things and you want to do even more.  It’s more fun.

Why don’t you try adding a bit of hormesis into your daily activities? 

Try a little bit today.  Slowly does it.  But you can build up in the knowledge that indulging in a bit of stress, a smidgeon of hormesis, will help you reap the benefits of a longer, healthier life.

Articles You Might Like

10 Brilliant Reasons to Challenge Yourself

Beyond Scary: Bucket List Lessons from Adrenaline Junkies and Toddlers

24 thoughts on “Hormesis 101: Small Doses of Stress to Live Longer”

  1. Avatar for Rosemary Bointon

    Like a lot of things, it can be an acquired taste – I find I go through phases of liking to drink it and then going off it. But knowing that it does you good is a bit of an incentive.

  2. Avatar for Rebecca

    Interesting, so we all need a bit of Hormesis in our lives! I struggle a bit with green tea too but perhaps should aim to have a few cups a week.

  3. Avatar for Cathy Hutchison

    Rosemary, I LOVE this article! I also love it that you are the type of adventurer who would walk into an icy mountain stream. WOW, you are a serious badass!

    I hadn’t thought about this topic in all the different ways stresses are actually good for us. After all, sitting on the couch involves no stress at all and it does not produce a “long life fun life!”

    PS. THANK YOU for that chocolate graph! Thank you! Thank you! Thank you!!!

  4. Avatar for Rosemary Bointon

    Awwwwh – Cathy, you’re too kind. I found it a really interesting subject. It does give a different way of looking at the world and seeing that things we find difficult are not all bad. I find that really comforting.

    And yes, I thought the chocolate chart was great. Finding the right dose is a great sport! (I’m definitely guilty of overdosing on chocolate!)

  5. Avatar for Kathryn

    Hi Rosemary
    Very enlightening article. Adding blueberries and avocados this week slowly to my diet.
    With the spring coming and a day or so of warmer weather, I will be getting outside and running around as the article says. Everything in moderation. Trying new things a little bit today. Build up in the knowledge that indulging in a bit of stress, – hormesis, will help us reap the benefits of a longer, healthier life. And who doesn’t want that?

  6. Avatar for Subhajit Banerjee

    I knew that incremental improvent is the key to everything, but I didn’t know that it can be applied in such a controlled and structured manner. Fascinating concept Rosemary, thanks for sharing this!

  7. Avatar for D

    What a great article! I already do some of these, but plan to implement some more. A big aha for me connecting dosage as key beyond medicine. Thank you, Rosemary!

    1. Avatar for Rosemary Bointon

      Thanks, D’Anne. Yes, I found the whole topic fascinating and couldn’t resist writing about it – even though it seems a bit obscure. In fact, it’s a funny mixture between the obscure and everyday thinking. Glad it gave you an aha!

  8. Avatar for Ryan K Biddulph

    AHA Rosemary! Right up my alley. I took an icy cold shower for the first time in months today. Felt awesome. Brutal, because I lost the mojo – after doing it daily for a long time – but still, amazing stressor leading to growth, wellness and longevity. I would suggest meditating and doing Kriya yoga. Kriya yoga in particular introduces all types of stress through severe tension. Definitely digs up fear-pain-grief-repression, something all of us need to face, feel and release, to be liberated. Fabulous post.


    1. Avatar for Rosemary Bointon

      Thank you! The feeling after cold showers is amazing, isn’t it? Glad you found your mojo! Kriya yoga – I must investigate that. Isn’t it weird how we stop doing things even when they make us feel better? I do that with ordinary yoga. Will do it religiously for a good while and then it sort of peters off until I ‘discover’ it again. Then I wonder why on earth I stopped doing it.

  9. Avatar for Joy Healey

    Hi Rosemary,
    Interesting article. Although I understand the concept of hormesis (from chocolate and wine!) I hadn’t come across the word before.

    During UK lockdown I’m no longer doing 5:2 fasting, but before that I was – and finding it suited me well. I’ll go back to it when “all this” is over.

    Funny to think people could read this in years to come and wonder what “all this” was – haha. This too will pass :-)

    Joy Healey – Blogging After Dark

    1. Avatar for Rosemary Bointon

      Yes, it’s actually quite a basic concept in my view, but you’re right, it’s not well known, which is why I found it interesting.

      5:2 fasting can be really effective. My sister in law did really well on it and so I tried it too and found it helpful. But any kind of fasting is a bit of a stress on the body, so when you’re loaded up with even more of it, as we all are at the moment with this crisis, it can be a really good idea to let go of extra stresses. So good for you!

      Interesting that you think people will wonder what this crisis was all about. It makes me think of the Black Death that ravaged Europe back in the Middle Ages and then the Spanish flu (which apparently started in Kansas and not in Spain at all – not sure of the details) after the First World War. We haven’t forgotten those and we have songs that we sing to commemorate them. Think of ‘Ring-a-ring of roses’. That was for the plague. Got any songs that you think would fit this crisis?

      1. Avatar for Joy Healey

        Hi Rosemary,
        Well after the Queen’s ‘lock-down’ speech here in the UK it seems to be “We’ll meet again” :-)
        Stay safe and well!
        Joy Healey – Blogging After Dark

  10. Avatar for Susan Hutchison
    Susan Hutchison

    Wow! Really interesting article Rosemary. Love your explanation of hormesis. And your photos, especially the one of you stepping out into a glacial stream. Thinking on it, when my life gets happily very busy and good stuff flows in, I can feel ‘stressed’ in a positive way. And as food has been my emotional comforter in the past, I can sense the same pull to use it in these seemingly challenging times! Thanks for touching on all the different aspects of hormesis. I’m certainly the wiser for it :)

    1. Avatar for Rosemary Bointon

      Thank you Sue. I found it a fascinating topic – and one I’m sure I’ll come back to. I’m lucky in that I don’t turn to food in times of stress – I read cosy mysteries and romances which take my mind off the stress.

  11. Avatar for Mitch

    That cold lake photo is classic! For me it’s weird, sometimes cold water leaves me refreshed and energized. Other times I feel super tired after. I wonder if too cold too soon is too much of a shock to the body – maybe you have to work up to it!

    1. Avatar for Rosemary Bointon

      I think it’s something to work up to. Plus I find it really depends how I’m feeling. When I was ill, it was all a bit too much but getting into it again gradually really helped. It also has to be regular to yield best results! In my experience, (limited as it is), I find that the ability to stand the cold wears off and you have to build up to it again. Those lakes you’ve been swimming in look seriously cold! It must put you off washing!

Leave a Comment

Your email address will not be published. Required fields are marked *

I accept the Privacy Policy

5 Challenges

for a Longer Fun-filled Life

By signing up for this guide, you will also be added to my mailing list. You will receive periodic updates and special offers from me via email. I will not sell or distribute your email address to a third party at any time. View our privacy policy.

How to Sleep Better: 33 Expert Tips for a Good Night's Sleep

I am sending your PDF download link to your email. By signing up for this PDF, you will also be added to my mailing lists.  You will receive periodic updates and special offers from me via email.  I will not sell or distribute your email address to a third party at any time.  View our privacy policy here.

So you want your sleep tips as a PDF?

Your PDF link will be sent to your email address. By signing up for this guide, you will also be added to my mailing list.  You will receive periodic updates and special offers from me via email.  I will not sell or distribute your email address to a third party at any time.  View our privacy policy

Want your guide as a PDF?

Your Dream Trip: the Ultimate Guide to Senior Travel

Your PDF link will be sent to your email address. By signing up for this guide, you will also be added to my mailing list.  You will receive periodic updates and special offers from me via email.  I will not sell or distribute your email address to a third party at any time.  View our privacy policy

Want your guide as a PDF?

The Gig Economy for Boomers: the Ultimate Guide