Everything you know about exercise is wrong
October 7, 2020 Dovie SalaisHave you ever thought about how weird gyms are? How odd it is to pay…
Have you ever thought about how weird gyms are? How odd it is to pay someone else to encourage you to work up a sweat? That’s because exercise – defined as voluntary physical activity undertaken for the sake of health and fitness – from an evolutionary perspective is entirely unnatural. And not just unnatural, but commodified, medicalised, and virtue signalling.
umans never evolved to exercise but invented it in response to post-industrialised living, which means we have normalised the abnormal – running on the spot while going nowhere inside a sterile air-conditioned space, or lifting heavy items that do not require lifting. Yet without exercise, we can become ill and die early. We need it – that is, we need physical movement – but do we need all the misconceptions and misinformation that goes with it?
In a new book, Exercised, Harvard evolutionary biologist and running expert Daniel Lieberman debunks a host of entrenched exercise myths. He says we have become exercised – vexed, anxious, worried, harassed – about exercise, and that it is a recent phenomenon and could perhaps be regarded as slightly insane from the perspective of people living outside the sedentary developed world.
To illustrate this, Lieberman begins by transporting – with considerable difficulty – a Western gym treadmill to a remote subsistence farming community in Pemja, Kenya. He wanted to measure how local women walk while carrying heavy loads on their heads, but the treadmill made them walk awkwardly and self-consciously. It was, he says, “an illuminating mistake”, leading to the crux of the book: we never evolved to exercise. (Treadmills, he reminds us, were invented by the Romans to turn winches, then remodelled by Victorian inventor William Cubitt in 1818 to punish prisoners – including Oscar Wilde. The idea of individuals paying to use them voluntarily is recent.)
“There’s nothing wrong with treadmills,” he tells me. “We have evolved to be physically active, which we confuse with exercise. We have made exercise a virtue, but there’s nothing virtuous about it.” Instead, we have turned exercise into a paradox: “Salubrious but abnormal, intrinsically free but highly commodified, a source of pleasure and health but a cause of discomfort, guilt and opprobrium.” Dismissing what he terms “inexcusable finger-pointing”, Lieberman says, “There’s nothing wrong with not wanting to exercise. We make people feel bad, which is shaming and unfair. Why can’t we make it fun?”
⬤ Myth #1
We evolved to exercise
No we did not, says Lieberman – we evolved to be physically active. “Every day of their lives, hunter gatherers and subsistence farmers engage in hours of hard physical work,” he says, such as walking miles over rugged terrain, and ploughing, digging and carrying without the aid of machines. Gym membership largely belongs to us, the WEIRD demographic – Western Educated Industrialised Rich Democratic – who account for only 12pc of the global population. In 1960, half of all US jobs involved moderate physical activity; today it’s less than 20pc. This accounts for enough annual surplus calories – 26,000 – to run 10 marathons.
⬤ Myth #2
It is unnatural to be indolent
Nope – humans (and other primates like chimpanzees) evolved to conserve energy, and to avoid unnecessary exertion. Yet a 2016 survey found how three out of four North Americans think obesity is a result of a lack of willpower around exercise and appetite control. “Rather than blame and shame each other for taking the escalator, we’d do better to recognise that our tendencies to avoid exertion are ancient instincts that make total sense from an evolutionary perspective,” writes Lieberman. The Sabbath, originally mentioned in the Old Testament, was fundamentally about having a day off for sex: to “be fruitful and multiply.” Inactivity is an energy-saving device, for which we are hardwired, just as we are hardwired to seek out fat and sugar in food; but in 21st-century developed societies, this works against us.
⬤ Myth #3
Sitting is intrinsically unhealthy
It is emphatically not the new smoking, says Lieberman, who consulted Irish back-pain expert Kieran O’Sullivan on the subject. It’s not sitting that’s the problem, but the hours of inactive sitting combined with not enough exercise in our WEIRD lives. “Standing desks have been widely advertised as a panacea for excess sedentariness,” writes Lieberman. “Such marketing deceptively confuses not sitting with physical activity.” It is leisure-time sitting which is the biggest mortality predictor, linked with socioeconomic status and exercise habits during time spent away from sitting at a work desk. The desk-to-sofa trajectory is not a healthy one.
⬤ Myth #4
You need eight hours’ sleep every night
Lieberman questions the idea that we supposedly sit too much but don’t sleep enough, despite both being states of inactivity. While reiterating the profound importance of sleep, he questions what is “normal” sleep for a “normal” human and looks at how the eight-hours recommendation is “industrialised sleep”, to fit around the Western work schedule. A UCLA study found how hunter gatherers in Tanzania, the Kalahari desert, and the Bolivian rainforest – none of whom have electric light, alarm clocks, or nine-to-five jobs – slept less than Western workers. Amish farmers, rural Haitians, and Madagascan subsistence farmers sleep 6.5-7 hours a night; a study of one million Americans showed those who sleep the full eight hours had a 12pc higher mortality rate than those who slept 6.5-7 hours. We have adapted to sleep less than chimps. Relax, says Lieberman, if you wake up in the middle of the night, it’s fine. Referring to the “sleep industrial complex”, he notes wryly how “there’s money to be made from insomnia”.
⬤ Myth #5
Normal humans trade off speed for endurance
“We can train our bodies to do an astonishing range of things, and while some workouts must favour our inner hare or tortoise, why can’t we do both?” asks Lieberman. He says that such duality is highly effective, and favours High Intensity Interval Training (HIIT) to access both speed and endurance. Our Stone Age ancestors did not train to sprint 100m in a straight line, but instead “evolved to be good at a wide range of athletic challenges”.
⬤ Myth #6
We evolved to be extremely strong
No, but we did evolve to lift and carry – children, water, food, tools. The American College of Sports Medicine recommends twice-weekly bouts of strength training – 10-12 reps of 8-10 different resistance exercises – until the age of 65, after which the reps should increase to 10-15. Yes, increase – older muscle needs more work. However, Lieberman reminds us that for overall health, cardio is more important.
⬤ Myth #7
Sports = exercise
Sport evolved from play, rather than from a need to exercise, and is fundamental in all human cultures. Almost all baby mammals learn the skills needed to fight and hunt as adults; play also helps young mammals, including humans, with social hierarchies, to be able to forge co-operative bonds and defuse tensions. Modern sport comes from chasing, tackling, throwing projectiles and so on, while controlling aggression. Billions of us love to watch sport, as well as take part in it. Physically and mentally, it is beneficial – playing is not just for juvenile mammals, but for all. It’s bigger than exercise.
⬤ Myth #8
You can’t lose weight by walking
You can, but you need to walk briskly for at least five hours a week to do so. Dieting is more effective for initial weight loss, says Lieberman, but exercise is key in preventing regain. (Which is where we all fall down.) And walking is fundamental to all humans, despite it no longer being about endurance unless you are a hunter gatherer, or live far from the nearest water source. A daily 10,000 steps (almost five miles) walked briskly will burn 250 calories – but Lieberman reminds us that running the same amount burns more fat. Walking is good for maintenance.
⬤ Myth #9
Running is bad for your knees
Not if you know how to run – it’s a skill, the same as swimming, and needs to be learned. It’s all about using the cushioned ball of the foot, rather than the heel. And while Lieberman thinks that apps like Couch to 5K are “wonderful”, he reminds us that the aerobic body adapts faster than the musculoskeletal body, so you might not be out of breath the more you practise running, but your joints could hurt. “It’s a design flaw,” he says. However, he says that “humans run as efficiently per pound as horses, antelopes and other species well adapted for running”. We just need to learn how to do it properly.
⬤ Myth #10
It’s normal to be less active as we age
“Staying active becomes more important as we age, not less,” says Lieberman. “We evolved to be grandparents and to be active grandparents. There should be no such thing as retirement.” Over millennia, longevity has been promised by everything from mercury and ground dog testicles to human growth hormones and vitamin megadoses. The most sensible advice, however, has always included exercise: “Regular physical activity slows the ageing process and helps prolong life.” So don’t stop. Instead, do more.
Just as Michael Pollan urges us to eat food, not too much, mostly plants, Daniel Lieberman offers similar advice, relating to physical activity: “Make exercise necessary and fun. Do mostly cardio, but also some weights. Some is better than none. Keep it up as you age.”
He is convinced that “a philosophy for how to use one’s body is just as useful as a philosophy for how to live one’s life”.
Because we only get one body – we need it to last.
