The exercise news today is something that older readers may already have taken on board, namely that walking is not only good for one’s cardio-vascular health, but can also fire up the brain, and who doesn’t need their brain fired up. This is the message of a new book, In Praise of Walking by neuroscientist, Shane O’Mara:
This book was released only today (1 August 2019), and here is Alor.org, so fast that we already have a review (of a review):
“O’Mara’s enthusiasm for walking ties in with both of his main interests as a professor of experimental brain research: stress, depression and anxiety; and learning, memory and cognition. “It turns out that the brain systems that support learning, memory and cognition are the same ones that are very badly affected by stress and depression,” he says. “And by a quirk of evolution, these brain systems also support functions such as cognitive mapping,” by which he means our internal GPS system. But these aren’t the only overlaps between movement and mental and cognitive health that neuroscience has identified. I witnessed the brain-healing effects of walking when my partner was recovering from an acute brain injury. His mind was often unsettled, but during our evening strolls through east London, things started to make more sense and conversation flowed easily. O’Mara nods knowingly. “You’re walking rhythmically together,” he says, “and there are all sorts of rhythms happening in the brain as a result of engaging in that kind of activity, and they’re absent when you’re sitting. One of the great overlooked superpowers we have is that, when we get up and walk, our senses are sharpened. Rhythms that would previously be quiet suddenly come to life, and the way our brain interacts with our body changes.”
From the scant data available on walking and brain injury, says O’Mara, “it is reasonable to surmise that supervised walking may help with acquired brain injury, depending on the nature, type and extent of injury – perhaps by promoting blood flow, and perhaps also through the effect of entraining various electrical rhythms in the brain. And perhaps by engaging in systematic dual tasking, such as talking and walking.” One such rhythm, he says, is that of theta brainwaves. Theta is a pulse or frequency (seven to eight hertz, to be precise) which, says O’Mara, “you can detect all over the brain during the course of movement, and it has all sorts of wonderful effects in terms of assisting learning and memory, and those kinds of things”. Theta cranks up when we move around because it is needed for spatial learning, and O’Mara suspects that walking is the best movement for such learning. “The timescales that walking affords us are the ones we evolved with,” he writes, “and in which information pickup from the environment most easily occurs.”
Essential brain-nourishing molecules are produced by aerobically demanding activity, too. You’ll get raised levels of brain-derived neurotrophic factor (BDNF) which, writes O’Mara, “could be thought of as a kind of a molecular fertiliser produced within the brain because it supports structural remodelling and growth of synapses after learning … BDNF increases resilience to ageing, and damage caused by trauma or infection.” Then there’s vascular endothelial growth factor (VEGF), which helps to grow the network of blood vessels carrying oxygen and nutrients to brain cells. Some people, I point out, don’t think walking counts as proper exercise. “This is a terrible mistake,” he says. “What we need to be is much more generally active over the course of the day than we are.” And often, an hour at the gym doesn’t cut it. “What you see if you get people to wear activity monitors is that because they engage in an hour of really intense activity, they engage in much less activity afterwards.” But you don’t get the endorphin high from walking, I say. “The same hit you get from running is what you’d get from taking morphine? We simply don’t know that’s true,” he says. “People who study this area don’t go on about endorphins and there may be a reason for that.” Not that he is opposed to vigorous exercise, but walking is much more accessible and easily woven into everyday life: “You don’t need to bring anything other than comfy shoes and a rain jacket. You don’t have to engage in lots of preparation; stretching, warm-up, warm-down …” O’Mara gets off his commuter train a stop early so that he can clock up more steps on his pedometer. To get the maximum health benefits, he recommends that “speed should be consistently high over a reasonable distance – say consistently over 5km/h, sustained for at least 30 minutes, at least four or five times a week.”
Basically, for people over about 60 years, maybe less, exercises like weight lifting, various sports such as squash, may be too stressful. But, from walking one can get everything. Humans were made to walk, and no land creature can out-walk humans, with beasts being hunted to exhaustion by light-skinned human hunters, their fur causing the animal to ultimately collapse. Now we know brains are wired so that walking can stimulate neural repair and health. So, walk every day!