I used to think about health largely in terms of three things: toxicity, deficiency and stress.

There is truth in that model. What we are exposed to, what we put into our bodies, what we lack, and the stresses we experience can all influence our health.

But I’ve come to see it differently.

Perhaps the more useful question isn’t simply “What causes illness?”

Perhaps it is:

“What can we do to create the conditions in which the body remains resilient?”

This shifts the focus away from constantly looking for something that has gone wrong and towards supporting the body’s ability to adapt, repair and recover.

And one of the most interesting places to look is the mitochondria.

Mitochondria are more than our cellular batteries

Mitochondria are usually described as the powerhouses of our cells because they produce much of the energy our cells need.

But they do much more than that.

They are involved in cellular signalling, metabolism, calcium regulation, immune responses and the processes by which cells respond to damage.

They are also remarkably adaptable.

The health of our mitochondria is influenced by the environment in which our cells exist — including nutrition, movement, sleep, stress, hormones, inflammation and metabolic health.

So perhaps supporting mitochondrial health isn’t about finding one magic supplement or eliminating one particular toxin.

Perhaps it is about creating the right conditions for the body to continually adapt and repair.

1. Nourish the body

The first foundation is obvious but often overlooked: give the body what it needs.

Mitochondria require energy, amino acids, fatty acids, vitamins, minerals and numerous cofactors to function.

That means nutritional adequacy matters.

It also means that continually restricting food or nutrients isn’t necessarily synonymous with health. There is a difference between eating in a way that supports metabolic health and chronically under-fuelling the body.

The goal is not simply to eat less.

It is to provide the raw materials required for the body to function and repair itself.

2. Move the body

Movement is one of the most powerful ways we can stimulate mitochondrial adaptation.

Muscles respond to physical demand by adapting their energy-producing capacity. Regular exercise can stimulate mitochondrial biogenesis and improve the ability of muscles to use energy efficiently.

This doesn’t mean that more exercise is always better.

The body needs a balance between challenge and recovery.

Walking, resistance training, cardiovascular exercise and simply avoiding prolonged inactivity can all have a place.

The important principle is that the body needs a reason to adapt.

3. Recover

Adaptation doesn’t happen simply because we place demands on ourselves.

It happens during recovery.

Sleep is particularly important because it provides a period in which numerous regulatory and repair processes can take place.

Chronic sleep deprivation is itself a physiological stress.

So if we’re exercising more, eating carefully and trying to improve our health while consistently sacrificing sleep, we may be undermining some of the very processes we’re trying to support.

Stress without recovery becomes a problem.

4. Learn to regulate stress

Stress isn’t inherently unhealthy.

In fact, some stress is essential. Exercise is a stress. Exposure to cold is a stress. Fasting is a stress. Even learning something difficult is a form of stress.

The issue is whether the body can respond to the challenge and then return towards equilibrium.

This is why psychological stress matters too.

Constant activation of the stress response without sufficient periods of calm and recovery can affect sleep, metabolism, immune function and many other systems.

The aim therefore isn’t to create a completely stress-free life.

It is to develop resilience and recovery capacity.

5. Support metabolic health

The mitochondria sit at the centre of energy metabolism, so metabolic health is closely connected to mitochondrial function.

How efficiently we handle glucose and fatty acids, how responsive our cells are to insulin, and how readily we can switch between different energy sources all form part of this picture.

This is one reason why diet, exercise, body composition and physical activity can have effects that extend far beyond weight.

Metabolic health is fundamentally about how effectively the body manages energy.

6. Respect the circadian rhythm

Our cells don’t operate independently of time.

The body has an internal biological clock that coordinates sleep, hormones, metabolism and many cellular processes.

Regular exposure to natural daylight, a reasonably consistent sleep/wake pattern and darkness during sleep can help reinforce those rhythms.

Modern life can make this surprisingly difficult.

Artificial light, irregular schedules, late-night stimulation and insufficient daylight can all interfere with the signals that tell the body when it is supposed to be awake and when it is supposed to repair and rest.

7. Reduce unnecessary toxic exposures

This brings us back to one of my original three principles: toxicity.

There is certainly value in reducing unnecessary exposure to harmful substances.

But I think there is an important distinction between sensible reduction of exposure and becoming frightened of everything in our environment.

We don’t need to create a completely sterile or toxin-free existence.

The body already has sophisticated systems for processing and eliminating many substances.

The goal is simply to avoid adding unnecessary burdens where practical.

8. Support hormonal and inflammatory balance

Hormones, metabolism, immunity and mitochondrial function don’t operate in isolation.

Changes in one system can influence another.

Chronic inflammation, hormonal disturbances and metabolic dysfunction can all alter the environment in which our cells operate.

This is why looking at health through isolated systems can sometimes be misleading.

The body is an interconnected network.

9. Give the body appropriate challenges

There is an interesting paradox here.

Some of the things we instinctively try to avoid may actually be useful in the right dose.

Exercise is a stress.

Fasting is a stress.

Cold exposure is a stress.

Learning and adapting are forms of stress.

These controlled challenges can stimulate adaptive responses — sometimes described as hormesis.

But this principle has an important caveat:

More is not necessarily better.

A small challenge followed by adequate recovery can build resilience.

A large challenge combined with inadequate recovery can simply become another burden.

10. Don’t neglect the human being

Finally, there is more to health than mitochondria.

Relationships, purpose, psychological wellbeing, time in nature, meaningful activity and a sense of connection all matter.

The brain is part of the body.

The nervous system communicates constantly with the immune, endocrine and metabolic systems.

So looking after ourselves psychologically isn’t somehow separate from looking after our physical health.

It is part of it.

The bigger picture

Perhaps staying well isn’t about finding the perfect diet, the perfect supplement or the one thing that is secretly making us ill.

Perhaps it is about repeatedly giving the body the things it needs to adapt, repair and recover.

Nourish.
Move.
Challenge.
Recover.
Sleep.
Regulate stress.
Maintain metabolic health.
Get daylight.
Reduce unnecessary exposures.
Stay connected.

None of these is a magic bullet.

But together they create an environment in which the body’s own systems have a better chance of functioning well.

And perhaps that is a more useful definition of health:

not the absence of all stress, but the capacity to meet life’s stresses, adapt to them, recover from them and remain resilient.