by Peter Walker
As is also common, the condition improved considerably into adulthood, but by then I had pretty much given up all activity except walking. This was partly due to my age – there are reams of statistics showing how childhood movement diminishes into adolescence and onwards – but, more importantly, I had lost faith in my body. Throughout university I was keenly aware of how unprepossessing a physical specimen I presented, ghostly pale and so un-muscular that the idea of wearing shorts, even a short-sleeved T-shirt, filled me with unease. I was also extremely conscious that if I did try anything connected to sport, I found the exertion increasingly difficult. I just wasn’t really sure what to do about any of it. Having graduated with no idea what I wanted to pursue as a career, I took up a dull if spectacularly secure job as a university administrator, spending all day at a desk. My path seemed set.
What changed was that I embraced that most basic and inescapable type of everyday activity: a manual job. More specifically, I became a bike courier, or messenger, spending all day pedalling urgent documents around London. Looking back, the reasons behind what appeared a pretty rash career move are still not entirely clear, especially given I’d not regularly ridden a bike since I was about twelve, and there was no set wage – you were paid entirely according to how many deliveries you made. I’d even decided to make the move to an outdoor job in autumn.
In retrospect the decision, which left my office colleagues politely baffled, was motivated as much by boredom as anything else. The university job involved a set series of tasks to complete over the course of a year, and without expending too much effort I’d managed to get them done about two months ahead of schedule, meaning I spent weeks with literally nothing to do. I also harboured vague, if unformed, notions of wanting to become fit, and this seemed one route to making such an outcome inescapable. Most trivially, I perhaps just thought bike couriers looked pretty cool, and as with many young men this was a quantity I both lacked and cherished.
Either way, the deed was done, and requirements as basic as my ability to buy food and pay the rent were suddenly dependent on those same scrawny legs being able to pedal me sufficient distances at a reasonable speed. The initial weeks were pretty terrible – I can remember almost bursting into tears when I saw how small my first wage packet was – but as I learned the trade the money became respectable, then even good.
I also got used to the exertion. Mine was a pretty drastic introduction to everyday movement, going immediately from almost nothing to a job where I would regularly cycle fifty or sixty miles a day, five days a week. But I was twenty-two when I started, an age when even such an untested body as mine tends to be hugely adaptable. First I developed a bit more speed on the bike, then stamina. After a while, in a turn of events that left me as surprised as anyone, my legs developed muscles.
Finally, for perhaps the first time in my life, I acquired that sort of virtuous glow only really seen among the young and physically fit. While I’d be lying to say I didn’t enjoy this new look, especially when people I hadn’t seen for some time pointed it out, it was the mental transformation that was more significant. It took perhaps six months for me to realise that, without even really noticing it, I had shed my unspoken assumption of physical frailty. In contrast, I suddenly felt I could do anything. That feeling, in varying forms, has never really left me, nor has the lingering sense of wonder and pleasure that comes with it.
It goes without saying that mine is a slightly extreme example. As we will see in the next chapter, most official guidance suggests you aim for a minimum of half an hour a day of moderate activity, while academics will tell you that even as little as ten minutes can do a lot of good. In the context of physical exertion being a miracle pill for human health and wellbeing, by cycling 250-plus miles a week, every week, I self-administered a mega-dose.
Since that sudden career change, which ended up lasting about three years, I’ve always remained active to greater or lesser degrees. I’m now middle-aged, with a family and a job which is both largely desk-bound and currently, amid the most chaotic political period in recent UK history, pretty frantic. I still cycle to and from work – or I do outside of lockdown – but that was often the most exertion I managed in a day. Researching and writing the book prompted me to look again at this part of my life, as did the restrictions of coronavirus, where my usual routine of bike commuting was halted. In particular, I was curious about whether my now more distinctly modest regime had kept me as physically impregnable as I had perhaps assumed.
I thus submitted myself as a sort of research guinea pig, festooned with electronic gadgets that tracked my movement, the time I spent sitting down, my heart rate, calories burned. I also underwent a series of tests of my fitness and general physical health. We’ll hear more about all this in later chapters, but without wishing to spoil the suspense, the data and examinations provided a more mixed picture than even I had expected. Yes, I remained significantly fitter than average. But in a few respects, not least the amount I sit down every day and the subsequent impact on my bodily composition, it seemed I had become a bit complacent. So make no mistake: for me this is very personal.
1 The Long Decline of Everyday Movement
Given this is the story of how our lives have changed so dramatically with the disappearance of everyday physical activity, it’s probably best to start at the beginning. And that might be slightly longer ago than you expected. About 12,000 years, in fact.
It was around this time that some of our Neolithic ancestors in what is now the Middle East gave up their hunter-gatherer lifestyle and, over numerous generations, began instead to cultivate crops, domesticate animals and form permanent settlements. This is, of course, not particularly long ago by the standards of human history – Homo sapiens had emerged anything up to 300,000 years earlier – but what is now known as the First Agricultural Revolution, or Agrarian Revolution, was the beginning of a settled, more densely populated life, helping bring about the development of new tools, then the specialisation of labour. In other words, the building blocks for modern civilisation.
Any 21st-century human suddenly catapulted to one of these first villages would find life there hugely gruelling and overwhelmingly physical. But it was still more sedate than the hunter-gatherer existence, free of the endless miles of walking required to forage and hunt for prey. And so, over the centuries, something began to happen to these early, home-dwelling humans: their bodies changed.
It has long been known that modern humans have considerably less dense bones than similar-sized primates, something often linked to our distinctive upright walking stance. But a fascinating 2014 study by US and British academics found that bones from humans who lived in hunter-gatherer communities in North America around 7,000 years ago (the agricultural revolutions did not happen everywhere simultaneously) were as strong and dense as those now seen in orangutans. In contrast, bones examined from farmers who lived 700 years ago were 20 per cent lighter. The researchers concluded that this ‘gracility’ of the more modern skeleton, a rather lovely technical term meaning ‘slenderness’, was not caused by a changing diet, or by different body sizes as humans evolved, but simply because of reduced physical exertion.1
Such change has very modern consequences. Human bone density is significantly affected by how active someone is, particularly during childhood and adolescence, with weight-bearing movements like running and jumping key to this development. Bone density usually peaks in early adulthood and then declines as we age, particularly with women, and all the more so through long-term inactivity. Loss of bone density increases the risk of fractures or the debilitating condition of osteoporosis, another evocative technical term which literally means ‘porous bones’. The health impacts are enormous. Studies have shown that among older people who suffer an osteoporosis-related hip injury, up to 20 per cent die in the first year, and two thirds never regain the same level of mobility.2
There is some important context to be added: in activity terms, these farmers clearly had m
uch more in common with hunter-gatherers than with today’s humans, so any bodily changes were relative. Another study examined bone mass in women from other early agricultural communities, this time in central Europe. It found that while the bones in their legs were generally comparable to those of modern women, with their arms it was a very different story. The humerus, or upper arm bone, showed rigidity and indications of strength comparable or even greater than that of modern-day elite female rowers. These women clearly carried or hoisted sizeable loads on a more or less daily basis, and they had the bone density to prove it.3
Gathering a more detailed picture of our ancestors’ physical lives is, understandably, not easy, short of using a time machine to attach an activity tracker to a prehistoric farmer’s leg. One creative part-answer has come from studying people whose lifestyles have at least something in common with those from the past. A fascinating project saw academics examine activity patterns in a community of Amish people in Ontario, Canada. The Amish are a Protestant group that originated in Switzerland but came to North America in the eighteenth century. As well as following a creed of non-violence, they pursue traditional values to the extent of rejecting all modern technology, meaning that – as regularly portrayed in films and television – their methods for everything from agriculture to travel involve nothing more high-tech than horses and hand-tools.
Luckily for researchers, Amish rules do not completely bar them from using modern inventions, just owning them. That meant the ninety-eight Amish men and women who took part were able to spend a week with an electronic step counter attached to the waistband of their trousers or to an apron – one slight complicating factor was that the Amish are forbidden to wear belts.
When the results arrived, they were striking. Separate surveys have calculated that the average Canadian adult walks just over 4,800 steps per day. In contrast, the Amish men averaged almost 18,500. Even the community’s women, who traditionally spend most of their time in domestic and child-rearing activities rather than farming, managed well over 14,000 steps.
The highest individual one-day total was 51,514 steps, more than 20 miles, recorded by an Amish man who was harrowing farmland, the process of smoothing and breaking up soil, while walking behind a team of five Belgian horses. The best for a woman was the 41,176 steps achieved by a farmer’s wife who rose at 3:30am to assist with the agricultural chores before beginning her own domestic duties. In such a world the idea of ‘exercise’ seems redundant. Of the men and women studied, only two – both men – listed leisure activities in the accompanying activity questionnaire, mentioning fishing.4
It is a very long time since Amish-style levels of exertion were the norm in places like the UK, a factor of both mechanisation and a shift away from rural life. Britain experienced a particularly early exodus of agricultural populations to factory jobs in towns and cities, with the country’s rate of urbanisation soaring from below 50 per cent in 1840 to nearly 80 per cent by the end of that century.5 But even decades after that, up to the post-war era of the 1950s, although for many people the repetitive physical grind of manual factory labour had been replaced by sedentary work, other aspects of life remained significantly more active than we experience now.
How do we know this for certain? One innovative experiment saw a group of volunteers fitted with sensors to measure how much energy they expended, before being set to work carrying out a series of identical household and transport activities in two different ways. They washed a selection of dishes in a sink, and then loaded the same number into a dishwasher. Dirty clothes were laundered by hand, then re-dirtied and put in a washing machine. An imaginary 0.8-mile commute was done on a treadmill to simulate walking, and then by car. Finally, our long-suffering test subjects ascended and descended a series of floors using the stairs, before doing so in a lift.
The results showed that hand-washing dishes and clothes was, as you would expect, more strenuous than the automated versions, by 40 per cent and 55 per cent respectively. But much greater differences came when the whole body was in motion. The simulated walking commute and the stair climbing were both more than three times as strenuous as letting machinery do the work. Factoring in how often people tend to perform all these tasks on average, the researchers calculated that these modern conveniences meant people now expend 111 fewer caloriesI per day on average.6
This might not seem much, given the recommended daily intake is 2,500 calories for men and 2,000 for women.7 But as the research paper pointed out, dropping your energy expenditure by 111 calories a day without a parallel reduction in food intake brings an average weight gain of more than 4kg a year, which is a relatively rapid path towards obesity.
Steven Blair is emeritus professor at the Arnold School of Public Health at South Carolina University. He is one of the world’s leading experts on how everyday movement has disappeared from the world, and the consequences. Blair was the lead editor of a landmark 1996 report by the US Surgeon General into activity levels, which kicked off much of the modern era of government guidelines on the subject.8 He is also, incidentally, one of the pioneers of the idea that it is far better for your health to be overweight and active, rather than slim and immobile, which we’ll hear more about later.
Blair is now aged eighty, old enough to remember first-hand how much things have changed in the home. ‘Do you want me to tell you who is the real cause of all of these problems?’ he tells me, his voice crackling with energy and mischief down the phone. ‘It was James Watt, inventing that steam engine. But to be serious, we’ve been engineering human energy expenditure down and down. I grew up on a farm in Kansas, and I didn’t have to do any exercise. I worked my tail off. At 5:30am Daddy would make me go out and get those cows in, and milk them, and feed them, and work all day. Thank goodness I did go to school, so there were a few hours during the school year when I didn’t have to be out there.
‘I remember when my grandma got a vacuum cleaner. I think it was 1944. And when my parents got electricity out on the farm, I didn’t have to carry all those logs in for Mom to put on the stove to cook dinner. On and on and on we’ve engineered human energy expenditure, down and down and down. I’m not saying we shouldn’t have these modern, wonderful devices, but what it means is, we’ve got to find ways for people to build a little more activity back into their lives.’9
A world immobile
Seven-plus decades on from the Blair family’s first vacuum cleaner, how inactive are we as a species? The short answer is: very – and probably even more so than even the official statistics indicate.
The long-standing way for academics to assess activity levels has been to use questionnaires. But as Blair or any other researcher of a similar vintage will resignedly tell you, people cannot always be trusted. My favourite summary comes from James Skinner, a now-retired professor of exercise science at Arizona State University, who once wrote, wisely: ‘As a general rule, people overestimate what they do, and underestimate what they eat.’ Skinner cited a US study in which people were asked to name which sports they took part in. Even allowing for some of them engaging in more than one sport, the number of people who reported doing just the top ten activities was greater than the entire population of the United States.10
Directly monitoring individual movements is now far easier, thanks to the advent of electronic activity tracking, familiar to anyone who has browsed the step count statistics on their smartphone. Many studies now use tiny, Bluetooth-connectable devices, which can feed researchers 24-hour flows of data about every movement and rest, however small or brief. I managed to borrow one of these research-grade devices to track my own activity levels, with eye-opening results, as we’ll see later in the book. All that said, when it comes to population-wide studies, especially ones comparing countries, much of the information still tends to be based on surveys and questionnaires. As such, however gloomy the global activity averages, it should be remembered that things are probably worse in real life.
When researchers investigate
whether people are considered inactive, thus risking their long-term health, the standard metric is failing to reach at least 150 minutes a week of moderately intensive activity, or 75 minutes of vigorous activity, ideally spread out over five or so days and in bouts of at least ten minutes. The precise definitions of moderate and intense are slightly complex, and I will detail them in the next chapter. But there are countless lists of suggested activities which give a good general idea. For example, moderate activity covers things like walking at a brisk pace, and more strenuous housework chores such as vacuuming, and gardening. To reach intense exertion levels you need to be running, or cycling fairly quickly, or doing difficult manual work like digging a ditch.
This 150-minute gauge has become more or less universal, and is used by the World Health Organization (WHO), Public Health England (PHE) and the US Department of Health, among others. It must be remembered that this is just a minimum level seen as necessary to maintain health, and yet many millions of people don’t get anywhere near it. The latest figures for England show that for adults, 66 per cent of men and 58 per cent of women meet these guidelines.11 This is, however, only part of the story. A more recent but now equally ubiquitous global recommendation from PHE, the WHO and others is that to preserve bone strength and prevent muscle wastage as people age, adults should do some sort of strength-based activity twice a week, whether lifting weights or something like carrying heavy shopping. When the requirements for both aerobic and muscular activity are taken into account, the proportion of people who reach the minimum falls to 31 per cent of men and 23 per cent of women.12