After the release of neuroscientist Professor Shane O’Mara’s first book, Why Torture Doesn’t Work: The Neuroscience of Interrogation, his literary agent, seeking ideas for another book, asked him what was his favourite hobby or recreational activity.
“I walk,” O’Mara replied matter-of-factly.
Shortly thereafter, he found himself thinking a lot more about it, and decided to write a book about the neuroscience and physiology of walking, coming to the conclusion that it is one of nature’s most unheralded superpowers.
O’Mara, a professor of experimental brain research at Trinity College Dublin, wrote In Praise of Walking: The New Science of How We Walk and Why It’s Good for Us.
He investigates walking’s relationship to human evolution, its physical health and psychological benefits, and the structural mechanics of it all.
Long interested in processes to do with how the brain learns, remembers, and is affected by stress and depression, O’Mara noticed similarities between past research and what he was finding out about walking.
“The brain is an unusual organ. It uses the same structures for multiple different purposes,” O’Mara, who earned his DPhil (PhD) at Oxford, explains.
“The part of the brain that is affected terribly by stress and depression is the hippocampal formation, which runs from your temple back to the top of your ear.
“It, in turn, is a part of the brain that supports your ability to remember things. But it’s also the part of the brain that is both involved in building the cognitive maps that we have of the world and that is preferentially activated when we walk.”
Talking to the Irish World, O’Mara demonstrated an example of the nourishment that movement can bring to your brain health.
“If you take a long journey on a motorway, at 80 or 100 kilometres per hour, you don’t remember very much of it, do you?” he asks.
“But if you take a walk, for the same hour, your ability to recall what you’ve encountered on that walk is actually quite good. This is because this part of the brain is activated at the speeds that we engage in when we’re walking.”
Outside of the endless research about patients walking post-injury, especially in cases of restoring walking after spinal injuries, O’Mara suggests there is a surprising lack of literature on the benefits of such exercise to our health.
His book, he sincerely hopes, will both spark a conversation in academia about the need to research walking more roundly and also for people to re-examine — or newly discover — the importance of movement in everyday life.
Walking is unquestionably fundamental to human existence, whether we acknowledge this consciously or take it for granted in our deepest subconscious.
But, O’Mara attests, we’re built, biologically, in an odd way such that countervailing ideas clash and create new behaviours.
“Movement is absolutely central to human nature. We’re built to be mobile, to get around in the world. But we’re also built to conserve energy: we’re lazy in a very particular sense in that we’re very good at going out at foraging and collecting food,” he says, giving the example of male hunter-gatherers, who scientists estimate trundled as many as 18 kilometers every day.
“But when you bring the food back, you rest. Getting food costs energy and you want to conserve it,” he continues.
“We’ve solved the problem of food gathering in the modern world…there is easy access to food almost everywhere. But what we haven’t solved, is how we can build movement into our everyday lives.
“This is a big urban design challenge, because more than half of the planet now lives in towns and cities.”
One of the biggest takeaways from his new book is exactly this: how the worlds in which we live — particularly urban regions like cities and towns — are not designed with human movement in mind.
Architects and planners, conversely, are forever finding new ways to limit walking distances, inspired by making everything easier for everyone, especially for those with reduced mobility.
Decisions about how movement can be fostered into buildings, O’Mara argues in the book, have to be “baked into building designs at the start”.
Removing as many cars, and as much traffic congestion as possible, is always worthwhile.
“This idea that movement is central to how we function as humans as something that architects, policymakers and road engineers really need to take on board,” he says.
“Once buildings are there, they’re there for a long time. So, for example, in Trinity College, where I work, in order to get to the stairs to come in, you have to go through three fire doors. Whereas, if you want to take the lift, it’s just there.”
If you don’t have mobility problems, you simply get out of your seat and walk, head and shoulders aloft. It’s an unthinking, unconscious act for most, a simple, inescapable fact of life.
O’Mara, on the other hand, marvels at the intricacies of even a short stroll.
“The brain, in essence, takes a decision to move. You decide where you want to go. You then send command signals from the brain, down through the spinal cord, into your feet to get you standing upright,” O’Mara explains, generously ensuring the topic can be understood by a layman.
“Then you have to move your body trunk and you have to figure out where you are and move toward where you want to go. This is surprisingly complicated, because in addition to making motor movements, you also have to have a map — somewhere in your head — of what your world looks like.”
This map he refers to — our internal, biological GPS — is only ever confronted when something goes wrong. (Alzheimer’s, dementia and other memory-loss illnesses can chip away at these GPS capabilities).
O’Mara recommends walking daily for one hour, or even just 45 minutes, at a relatively fast pace.
This, he found from research, “improves virtually every aspect of your being”: cardiovascular health; brain health; respiratory function (if you’re not living in a polluted area); gut health; and, most significantly, muscle health.
“At a more abstract level, we know that walking is very good for you psychologically. It assists with things like creativity,” he says.
“When you’re moving around, your whole brain is active in a way that it is not when you’re seated.”
Then there’s the social aspect of walking. After all, we descend from, and remain, social animals.
In humans, walking is unique in that it evolved in very distinctly social settings. Take walking down the street, if you’re strolling for a coffee, as O’Mara points out, you’ll walk at approximately the same pace as the person beside you. Synchronised behaviour is commonplace in walking.
“Walking, at its core, is social. Humans do things which are really quite remarkable. If you’re sitting there in one of Europe’s biggest cities, and people navigate complex, busy streets with people walking at them, across them and from behind them,” O’Mara says.
“We do this all without thinking, with the exception of momentarily being frustrated by your own inability to push somebody out. We walk together as a species. No other species does this.”
Our ancestors migrated — by foot — in small groups across the world. This meant that we had to be highly attuned to our surroundings. What, precisely, is going on with the people around us? Has somebody noticed a food source? Are we in an area where it’s safe? Can we sleep here? Can our children play here?
The very movement of walking, O’Mara says, is integral to understanding human evolution.
It is the centre of everything that makes us what we are. Our posture means that, since our hands are free while moving, we can quite easily gesture, point, gather, carry, attack, even eat, all while walking.
“There is little doubt about it that human bipedalism — being up on two feet — is the core of what makes us different to other [animals],” O’Mara explains.
“Our spine is in a considerably different position to others, including birds, many of which walk upright.”
Since other forms of exercise are more intensive, say jogging or sprinting, why does walking matter so much?
For most people, he answers, walking can be woven into everyday life more than it can for other forms of exercise, but he doesn’t dismiss their importance:
“Sitting around in a chair all day, munching bags of crisps, then going to a gym for an hour; that really isn’t the way to live your life.
“What you really need to do is get the level of movement up during the course of the day, which is the hardest thing to do.”
One of his favourite cities to walk in is London, where many of his old friends still live.
“I’ve had many long, wonderful walks in London,” he says, before acknowledging the extensive research findings that tell us walking in a green environment (rural or otherwise) is better for your health in so many ways.
He would love to spark a wider public conversation, from the point of view of neuroscience, to make us all think more deeply about walking in groups.
But he also wants to go beyond that. “To speak to the urban worlds that we live in, that we need to think about movement as the fundamental thing that humans were built to do,” as he puts it.
In his day job, he looks at experimental ideas in the field of brain science, at innovative ways of solving some of the mysteries of that organ.
Walking, by contrast, is simplicity itself. But this straightforwardness is radical.
“You have to ask: why do we have a brain at all? My general feeling has always been, we have a brain because we need to move,” he argues.
“Organisms that don’t have brains — trees, plants — don’t have any need to navigate a complicated and difficult environment.”