It is a common misconception that walking doesn’t have the same health benefits as going to the gym for an hour. Based on Shane O’Mara book In Praise of Walking, considering walking as not a proper form of exercise is a terrible mistake, as people who walk tend to engage in activity more consistently throughout the day. Furthermore, sitting at a desk all day compared to walking and talking gets our sensory systems to work at their best when they’re moving about the world.
In Praise of Walking cites a 2018 study that tracked participants’ activity levels and personality traits over 20 years and found that those who moved the least showed malign personality changes, scoring lower in the positive traits: openness, extraversion, and agreeableness. There is substantial data showing that walkers have lower rates of depression, too. And we know, says O’Mara, “from the scientific literature, that getting people to engage in physical activity before they engage in a creative act is very powerful. Furthermore, a notion, still to be tested, is that the activation that occurs across the whole of the brain during problem-solving becomes much greater almost as an accident of walking demanding lots of neural resources.
Walking has great benefits to those who have recently had an injury. O’Mara states 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. Rhythm’s is a big one for O’Mara who states that there are all sorts of rhythms happening in the brain as a result of engaging in walking that are absent when you’re sitting. One of the greatly 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
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 pick up 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 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.
O’Mara describes our inbuilt GPS, or cognitive mapping system, as a silent sense. “It is constructed largely without our awareness, and we only notice it if it fails us.” While the sensitive vestibular system of the inner ear governs balance, for mental mapping (which can work even when our eyes don’t), we have what are known as place cells in our hippocampi. If you stay in one place, the cell for that position keeps firing, but if you move, that cell will stop firing and a cell marking your new position will start firing and so on. In rat experiments, the system worked less well when the rodents were wheeled around as opposed to walking.
It’s clever, but not infallible. “We get fooled when we walk a long way in a single direction,” says O’Mara. We need to keep looking around us and recalibrating with visual cues.
Walking is alot simpler in some ways than other forms of exercise as it generally just requires some comfy shoes and a jacket. O’Mara recommends that to get the maximum health benefits from walking, “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.”