Are even surfaces stressful?

The debate surrounding running surfaces tends to focus on hard surfaces versus soft surfaces. This betrays an important blind-spot of our current running culture: we have forgotten where we came from.

Zoo-human perspectives and the surface blind-spot

In the 1960ies and 1970ies Desmond Morris, the British zoologist coined the term ‘zoo-human’, to describe our modern day permutation.The key feature of a zoological garden is the removal of the animals on display from their natural habitat and an almost complete cessation of the need of these animals for self-reliance. Many such animals – born in captivity – would find it impossible to find for themselves in their natural habitat. Desmond Morris observed how many of the ailments and illnesses befalling modern humans seemed to mimic the predicaments of zoo animals. His books imagery of  people clogged up in Brazilian favelas and shanty towns or American cubicles made the parallel unmistakable.   His thinking has guided much of the modern movements labelling themselves ‘wild’, ancestral, ‘Paleo’, ‘rewilding’, Primal, cave-man and ‘hunter-gatherer’. Today I am more interested in the errors in thinking drawn from our ‘zoo-human existence’ than the physical, sociological and psychological effects.

Since our actions are always determined by our desires and our desires are guided by our beliefs about the world, a zoo-human perspective can lead us to the wrong conclusions – even with correct facts – and therefore to make faulty training choices as runners.

The traditional running surface debate has a tendency to boil down to a simplistic focus on the unnatural hardness of certain man-made surfaces such as concrete over which most road races and training happens to occur. In order to counter this artificial hardness, we must adopt softer shoes and ensure we do a lot of running on grass – especially if we are heavier set. I have discussed this point on TodayFM Radio previously.

In the middle of the discussion of ‘hardness’ vs. ‘softness’ – or technically the level of ‘compliance’ – of a surface, another property eludes mention: variability and it is here that our skewed modern perspective makes itself known.

The solution: an evolutionary perspective

The discipline of Evolutionary Medicine* represents the hat I wear when I deal with injured runners or otherwise am involved in a coaching process where health matters are discussed or addressed. Evolutionary medicine uses insights into our original environment to explain disease etiology (‘why we get sick’) in modern environments. In ‘Evolutionary Coaching’ or ‘Evolutionary Training’ we need to wear this hat and asking the question:

‘how can we use an evolutionary perspective on the human body to guide us towards the right answers to address training issues?’

This will instantly remove you from the trap of zoo-human thinking. Now let us apply it to he question of running surfaces: we know that our ancestors must have moved across highly varied surfaces including both different levels of compliance and different levels of variation in surface traction, evenness, and other attributes. In terms of hardness this brings us to my original recommendation from the radio interview to always seek out a mixture of surfaces for running but not be afraid of less compliant ones – they are not the root cause of your problems.

* I want to alert the reader that Evolutionary Medicine, also called ‘Darwinian Medicine’ currently resides in its infancy partly because it is novel and partly because our understanding of evolution is far from complete and under constant revision. Today, the Paleolithic is used as an ideal comparison point to understand humans when very strong cases have been presented that we need to look much further back – to the Pliocene to truly understand what environment humans evolved to be healthy in. If you do want to inform yourself begin by reading ‘Why we get sick’ and ‘Mismatched’. If you are clinician you may then want to explore the weightier text-books available on the topic.

When safe is dangerous

The most unnatural surface we can imagine may be the synthetic running track. While it is more compliant than most road surfaces, it tends to be completely uniform. A coach or therapist with a zoo-human perspective will view this as an absolute positive and may be fretting about the day their fine thoroughbred stallion of a track runner has to enter his or her first cross-country race.

The coach or therapist with an evolutionary mindset recognises the synthetic track as a greater stressor – because he realises that there is a fundamental MISMATCH between the training and racing surface and the surfaces our human biology evolved to crave and expect. The greater the distance between what our biology expects and what it receives the more mismatches we will have – injury and illness are the end product of mismatches.

Uniformity – or lack of variation – harms biological creatures in almost all domains of life including training and an even running track presents one such stressor. Our foot and ankle evolved to expect a high degree of variability and expects almost every landing to be reasonably different from the previous and the next. When you take this variation away not only do you deprive the body of sensory input and movement experiences that it requires to continue to function optimally but you slow down your rate of learning because the neurological stimulus will be smaller – in other words: you challenge your brain more and thus gain greater motor skill adaptations by introducing more variation in the situations the body has to cope with. The more of this natural and expected variation you remove the more fragile – thus injury-prone – the organism becomes over time. This also affects the artificial running surfaces we create through running shoes – the more variability they remove from your foot-strike the more detrimental to your health and performance in the long-term.**

Variability only becomes detrimental when it rises to such a degree that the movement being practised ends up being entirely different – i.e. if I introduce a 10 metre stretch of bog in the middle of a track this would not be useful variation as a completely different movement than running would result.

** This does not include situations where removing a bit of variability to allow tissue healing to occur is mandated such as splinting a broken arm. But even this comes at a cost – the longer you keep something in a cast the weaker it will become and the longer the journey to return it to full strength. Our blind-spot to the dangers of ‘even surfaces’ has a definitive detrimental effect on the strength and vitality of our running culture.


We tend not to view ‘even surfaces’ as a stressor because we adopt a modern rather than an evolutionary perspective on training decisions. As we evolved on varied surfaces, our biology and performance suffers when we are deprived of this variety for extended periods of time. Too much running on even surfaces and in overly controlling shoes must therefore be avoided especially for children. Instead we need to embrace a wide variety of surface types and trust that our motor control systems evolved to quickly learn and adapt how to deal with these surfaces.

If we hold faulty modern beliefs about the benefits and risks of running surfaces it will guide our training choices in the wrong direction.