The Miracle Pill

by Peter Walker

  In one study, Tudor-Locke sought to put precise figures to this. Equal numbers of healthy men and women, split into five-year age groups between twenty-one and forty, were placed on treadmills, with their heart rates measured to see what speed was needed for them to reach moderate exertion. Averaging out the results, Tudor-Locke found that this was a cadence of between 100 and 130 paces per minute.23 She adds that when people count their steps over a timed minute, many find the 100-step pace ‘really quite slow’.

  Tudor-Locke explains: ‘It’s really easy for people to get to moderate intensity. So people say – why are we so worried? It’s because in our lives today we very rarely have purposeful walking for any long or persistent amount of time. We might walk from our car park to the office, and that might be the longest walk of the day. That might be a total of eighty steps. You haven’t even gotten to 100 steps, let alone 100 steps in a minute.’

  This leads to the second part of the equation: how much? It can be a source of some anguish for activity watchers, intensely aware of whether or not they have reached their 10,000-step target. Many people follow this on smartphones, but these measurements are often an approximation. As Tudor-Locke explains: ‘Men tend to wear their phones on them, for example in their pocket. But women tend to put their phone in their bag, which they then put down, and walk away from it.’ Wrist-worn fitness trackers and smart watches can be more accurate, but even these can be misled. As Tudor-Locke says during our phone call: ‘Right now, talking to you, I’m sitting on my butt, but my hands are flailing all around. I’ll be getting erroneous steps.’

  Does it even matter? The emergence of 10,000 as a step target has a slightly arbitrary history. In the wake of the 1964 Tokyo Olympics, a Japanese company devised and then marketed the first wearable pedometer, the grandfather of all the modern Fitbits. The original advertising shows it looking a bit like an old-fashioned nurse’s watch, with a dialled face hanging from a loop you could put on your belt. The key to the device’s legacy was its name: the manpo-kei, which translates from Japanese as ‘10,000-step meter’. This is the origin of the target.

  It wasn’t entirely marketing. The pedometer was devised by a young Japanese researcher, Dr Yoshiro Hatano, who had discovered that Japanese people were averaging only between 3,500 and 5,000 steps a day. His calculation was that boosting it to 10,000 could use up to 20 per cent of a person’s caloric intake and thus maintain a healthy weight. And yes, walking 10,000 steps is better than 5,000. But there is an argument that this would have been just as true if Dr Hatano had instead chosen 8,000 steps, or 12,000. Some researchers worry that the endless focus on 10,000 steps might seem a distant goal to the most inactive people, meaning they give up.

  Tudor-Locke notes that there can be a benefit in people having an easily remembered number to aim for, like five portions of fruit and vegetables a day, or 150 minutes of activity a week. But in terms of steps, she says, the important message is that everyone should simply try to walk at least a bit more than they do now, and at a slightly quicker pace: ‘If you walk further and faster, then the digits take care of themselves.’

  Whatever the reasons it was picked as a target, 10,000 steps does seem to be good for you. One recent study followed a large cohort of middle-aged people in the Australian state of Tasmania. It found that over the course of a decade, walking an average of 10,000 steps a day gave a 40 per cent reduced chance of death when compared to those who were largely immobile.24

  But as new research emerges, orthodoxies about both step amounts and cadence are being challenged. One groundbreaking study, published in 2019, was led, yet again, by the tireless I-Min Lee. It saw more than 16,700 older American women, with an average age of seventy-two, wear electronic step monitors for a week. When their walking data was analysed four years later, by which point 504 had died, the findings were remarkable.

  There was, indeed, a relationship between distance and mortality, but it began far lower than 10,000 steps. When the women were put into four groups based on step counts, those in the second lowest of these, with an average of 4,400 a day, had a 41 per cent lower risk of death over the period than those in the bottom quarter, who averaged 2,700. The benefits rose with greater step counts, but seemed to level off at around 7,500 steps a day.

  Another apparent anomaly was with the speed. Very few of these women, it is fair to say, could be described as routinely brisk walkers. In the four groups as ranked by step totals, between 93 per cent and 99 per cent of daytime hours were spent either not walking at all, or at a slow amble, up to a maximum of thirty-nine steps a minute – basically, pottering. That left very little time for fairly slow walking of between forty and ninety-nine steps a minute, while 100 steps or more – the supposed baseline for moderate exertion – barely happened at all, making up just 2.2 per cent of the time even among the most active group. And yet the health benefits were still visible.25

  One possible reason is that exertion is a relative state. Catrine Tudor-Locke’s 100-steps-a-minute assessment was based on much younger test subjects, and thus a significantly lower pace could still count as moderate for someone in their seventies. Also, as the study notes, it’s also simply possible that for older people the health benefits come as much from just being active at all than necessarily pushing yourself.

  This is a new boundary for activity research, Lee says: ‘In the past when we said, “You have to do at least moderate-intensity physical activity”, that wasn’t because we found that light-intensity activity was not beneficial for health, it was because we couldn’t measure it well. Now, if you look at some of the recent papers that have come out, we’re starting to see that light-intensity activity, which has not been recommended the way moderate- and vigorous-intensity physical activity have, is being shown to be beneficial for health. So I suppose it’s been surprising, and now the work is more about reinforcing that any little bit you can do is good for you. And that’s encouraging for a lot of people.’

  Step counting can still be useful, Lee says, but people don’t necessarily have to be fixated on 10,000 a day, especially if they are starting from a low base, and find it intimidating: ‘If you are someone who likes to count I would say that as a first goal, for someone who does nothing, try to reach around 4,000 to 5,000 steps. If you’re already at that, then 7,000 is a good next step. And if you’re at 7,000, then 10,000 is perfect. But, surprisingly, it’s a very low level you need to first get at and that’s the 4,000- or 5,000-step level. This is for the true couch potatoes.’26

  Anything is better than nothing

  This new era is gradually becoming reflected in the official guidance. A recent initiative devised by Public Health England, called Active Ten, has the very simple goal of trying to get people to walk briskly for ten minutes a day, whether or not it’s all in one go. The associated phone app, which monitors whether people have reached the target and politely cajoles them to do so, stresses in very large letters when it first opens that ‘every minute counts’.

  Similarly, the updated US PACAG guidelines from 2018 note for the first time that if someone is currently inactive, introducing even some light-intensity activity of more or less any type will reduce their risks of developing cardiovascular disease and type 2 diabetes, and of an early death. They also dispense with a previous assessment that bouts of activity should last at least ten minutes, saying any length is beneficial.27 Yet again, the key is to do something, of more or less any duration.

  Another new message public health officials are keen to push is the immediacy of the results. The PACAG report spells it out, saying that on the same day you manage a single session of moderate-to-vigorous physical activity you will see a reduction in blood pressure, better insulin sensitivity, improved sleep, fewer anxiety symptoms, and improved cognitive function. That’s not bad for an instant gain.

  At the other end of the spectrum, it’s worth noting that while there presumably is a maximum dose of activity beyond which the health benefits stop coming, it has not yet been fo
und, even if the dose–response curve does level off and beyond a certain level of extreme activity the health gains can become almost too negligible to measure.

  One of the most thorough examinations of this came in a 2016 meta-study comprising almost 150 million person-years of combined scrutiny. The overall conclusion was that while the biggest gains occurred at lower activity levels, their increase remained significant up to pretty Herculean amounts of movement. Using the tally of MET minutes per week – how many METs someone is moving at, multiplied by how many minutes they are doing it, over seven days – it took the standard 150-minute-per-week recommendation for moderate activity to stand for 600 MET minutes, assuming an exertion of four METs. If people managed beyond 600 minutes, they saw significant health gains, which only started to tail off slightly at 3,000 or 4,000 MET minutes per week.

  That’s between five and nearly seven times more than the minimum recommended amount. The authors helpfully provided a possible timetable for someone to amass even 3,000 MET minutes in a week, and it’s fair to say it sounds quite exhausting. The example involves – and remember, this should happen every day of the week – ten minutes of stair climbing, fifteen minutes of vacuuming, gardening for twenty minutes, running for twenty minutes, and walking or cycling for transport for twenty-five minutes. If you did follow this regime, as well as being fit, you would presumably also end up with a well-tended garden and extremely clean carpets.28

  Another consideration to bear in mind is how often you take your activity, whether gradually over a week, or in one or two short bursts. A fair proportion of people who meet activity guidelines in wealthier, industrialised countries like the UK fall under the semi-official public health category of ‘weekend warriors’. Such people are largely immobile on weekdays, often with a sedentary job and commute, and try to make up for it with a burst of sport, or activities like gardening. The verdict on this activity pattern is slightly mixed, and yet again a lot of it comes from studies led or co-authored by the ubiquitous I-Min Lee.

  An early attempt to look into this phenomenon, in 2004, found that for sixty-something weekend warriors at least, health gains were seen in people who did not have any risk factors, such as excess weight or a history of heart disease, but not those who did. In contrast, people who carried such a risk but were active throughout the week did experience benefits.29

  But a more recent Lee-involved study from 2017, which followed more than 60,000 English and Scottish people aged forty or older, found that while regular activity brought greater benefits, weekend warriors were still around 30 per cent less likely to die over the average nine-year follow-up period than people who were inactive. Importantly, the study found there were even gains for weekend warriors who did not reach minimum activity guidelines. As the authors noted: ‘Less frequent bouts of activity, which might be more easily fit into a busy lifestyle, offer considerable health benefits, even in the obese and those with major risk factors.’30

  There is the message again, and it is one that cannot be stressed enough: there are remarkably few circumstances under which being physically active for even slightly longer, or a bit more vigorously, will not do you some good. This accumulation of knowledge about the health dividends of even relatively tiny amounts of exertion is, like Richard Mackenzie’s examination of the cellular process of pre-diabetes, at the leading edge of inactivity research efforts. But as we will see in the next chapter, however numerous and varied the studies, they all ultimately originate from the same place: the remarkably little-known life and work of the extraordinary British scientist who first proved that everyday movement is good for us.

  Next steps:

  Try, if you can, to roughly tally how much activity you amass in an average week – how many minutes of moderate and/or vigorous movement. There are lots of useful web pages which give a full list of what activities count. You might be surprised how it all adds up, or you might realise you are, officially, inactive. And when you are walking, think about trying to do so briskly. Remember I-Min Lee’s adage about being able to speak but not necessarily sing.

  3 The Man Who Rediscovered Movement

  In 1948, as Britain began to tentatively emerge from its post-war fug of austerity, a young doctor of formidable intellect and apparently limitless energy took on a job that might have been created especially for him. There, he quietly decided to see whether he could change the world.

  This was Jerry Morris, a man whose amazing life story arguably merits an entire book of its own. Newly demobbed from service as an army doctor in India and Burma, Morris became director of the brand new Social Medicine Unit, a government-established body tasked with examining how health issues interact with people’s real-life circumstances. Morris was a quietly fierce, endlessly tenacious advocate for the societal changes that would help people to stay healthier. He also knew from personal experience that someone’s chances were greatly shaped by the background from which they came and the environment in which they lived.

  It was Morris’s stroke of genius to look into why the drivers of London’s double-decker buses had significantly higher rates of heart attacks than their conductor colleagues, and to eventually conclude that the only real difference between the groups was that the former spent their working days sitting down, while the latter were constantly on their feet, tramping up and down flights of stairs. Everyday physical exertion had to be the answer. After making this breakthrough, Morris spent decades politely haranguing government ministers to take action over it. That he largely failed says much more about the sheer weight of political lassitude and indifference he faced than about his own energy and far-sightedness.

  In fact, along with the slightly later but similarly influential work of Ralph Paffenbarger, a US pioneer of physical activity science who became a close collaborator and friend, Morris arguably did as much as any single academic to shape post-war thinking and knowledge. And yet, even in his own country Morris is barely known beyond specialist public health circles.

  These days, the idea that staying physically active is generally good for you might seem so obvious that it is almost difficult to believe this was not always known. But Morris’s landmark academic paper setting out his findings was only published in 1953, a few years after other researchers had connected smoking and cancer.

  Even more extraordinarily from a modern viewpoint, the discovery was seen, at first, as significantly controversial. Part of this was the need to overturn decades of scientific orthodoxy, in particular the persistent if entirely ill-founded idea that significant physical effort was bad for the heart.

  But also, the breakthrough came just as society-wide moves towards a more inactive world were really taking hold. Millions of people in Britain were gratefully enjoying the embrace of labour-saving household goods, and cars. They were, perhaps understandably, not so welcoming of the idea that the more gruelling, materially deprived period they had just been through might in some ways have been better for them. This arguably helped set the tone for subsequent decades of public and government inaction, something long apparent to Morris.

  It is a paradox of Morris’s discovery about movement and health that however contentious it was at the time, the idea would have seemed notably less surprising to practitioners a couple of millennia before. The history of medicine is littered with doctor-sages extolling the health benefits of regular exertion. Most famous was Hippocrates, the ancient Greek physician and founding figure of medicine, who 400 or so years before the birth of Jesus was pronouncing that ‘food and exercise, while possessing opposite qualities, yet work together to produce health’. He was also the first medical practitioner recorded as prescribing movement as an individual treatment, writing that a patient with consumption should seek to walk regularly.

  For centuries this was considered perfectly ordinary advice. ‘Of all the causes which conspire to render the life of man short and miserable, none have greater influence than the want of proper exercise,’ wrote William Buchan, the celebrated eighteen
th-century Scottish doctor and author in his hugely popular book Domestic Medicine, a publishing phenomenon of the era which was translated into numerous languages.1

  But as modern medicine emerged in the Victorian era, exertion began to be seen as almost a problem. Just under a century before Morris’s discovery, another single-minded and now largely forgotten medic-campaigner, Edward Smith, who had already led a colourful life including a brief spell selling land to fellow Britons in Texas, investigated conditions at the evocatively named and long-closed Coldbath Fields Prison in London. There, inmates sentenced to hard labour were punished by spending several hours a day on a so-called treadwheel, where a long line of men would turn a huge, cylindrical wheel with steps on it by pushing down with their feet, as if ascending an endless flight of stairs.

  Originally designed to pump water or mill grain, later treadwheels, as in Coldbath Fields, just turned a fan, something the prisoners ruefully called ‘grinding the wind’. Smith, who had a pioneering interest in measuring ventilatory volume – how much air someone breathes in and out – went to the prison with the assumption that such exertion would be inevitably bad for the prisoners’ wellbeing, writing that it must ‘induce disease and a premature death’. But when Smith actually examined them, he found, as you might expect, that their cardiovascular health seemed fine. What ailments they suffered, Smith discovered, were mainly caused by a diet that provided nowhere near the amount of nutrition needed for such a physical regime.2

  By the time Morris and Paffenbarger were emerging, some tentative studies were being carried out into the long-term health impact of activity and exercise. But these seemed mainly based around the worry, popular since the Victorian era and tied inexorably to the in-built, snobbish assumption that a gentleman’s chair-bound lifestyle must be the preferable one, that increasing one’s heartbeat and raising a sweat was damaging for your health, not to mention a bit undignified.