Exercised: Why Something We Never Evolved to Do is Healthy and Rewarding

Being a health and wellness guy, this book was right in my wheelhouse and it was a compelling, interesting, and detailed read by a very astute and smart guy who is incredibly insightful, honest about the “history” of exercise. However, check out these puzzling and paradoxical conclusions (at least from a present-day perspective): we never evolved to exercise, many of our beliefs and attitudes about exercise are myths, we are not supposed to “want” to exercise, and our tendencies to avoid exertion are ancient instincts that make total sense from an evolutionary perspective. How about that! Lieberman goes into great detail describing our ancestors, hunter-gatherers, early day Homo, and research on modern, non-industrialized tribes such as the Hadza who most exhibit the lifestyles of humans from ages ago. It turns out that energy (food) was a scarce resource back in the day, and our predecessors needed to save as much of that energy as they could when they weren’t scrounging or foraging for food or doing the work they needed to do to survive wherever they lived. So, for us couch potatoes, it makes sense for us to grab the TV remote and sit as much as possible whenever we can, but, obviously, we don’t have the same energy deficits because food, water, and other resources are readily available to us — virtually at any time, on-demand. The problem now, of course, is that we humans consume more resources (food) then we “burn” with everyday activity and exercise, causing an imbalance that has lead us to be stricken with chronic disease, inflammation, excessive fat stores, and overburdened hearts and arteries that lead to avoidable deaths. A super interesting book with a host of detailed research, one for the health and wellness pro’s but also for everyday folks who want to learn a few tips to live a happier, healthier, and longer life — with exercise leading the way.

  • main theme of the book: we never evolved to exercise
  • exercise today is most commonly defined as voluntary physical activity undertaken for the sake of health and fitness — recent phenomenon
  • exerceo: to train, practice
  • exercise — first used in middle ages to connote arduous labor like plowing a field
  • treadmill like devices first used by the Romans to turn winches and lift heavy objects, then modified in 1818 by Victorian inventor William Cubitt to punish prisoners and prevent idleness
  • many of our beliefs and attitudes about exercise are myths
  • chief is the notion that we are supposed to want to exercise
  • Just Do It is just as helpful as Just Say No
  • why and how is something we never evolved to do so healthy?
  • almost all studies of humans focus on contemporary Westerners or elite athletes
  • unrepresentative of our evolutionary past
  • genes play a key role in our motivation to exercise in the first place
  • but, failed to identify specific genes that explain much about athletic talent, like Kenyan runners
  • theory of natural human, Rousseau, “savage” state of nature reflect our true, inherent selves uncorrupted by civilization
  • this has been discredited, as has the myth of the athletic savage
  • Tarahumara men — training that enables them to run back to back marathons is the physical work that is part and parcel of their everyday life
  • myth of the athletic savage trivializes the physical and psychological challenges faced by all athletes everywhere
  • Hadza — when they aren’t being active, they typically rest and do light work
  • typical human workday used to be about 7 hours
  • hunter gatherer physical activity level (PAL) about the same as factory workers and farmers in developed world — about as physically active as Americans or Europeans who include about an hour of exercise in their daily routine
  • exercise outside of the context of sports was extremely rare until recently
  • first Jews were subsistence farmers whose survival depended on regular hard labor
  • majority of calories that humans consume are devoted to paying for the most basic needs of your body at rest
  • even if you are a highly active person, you probably spend more energy maintaining your body than doing stuff
  • when you starve yourself, your body transforms to use less energy even while resting
  • resting metabolism is what the body opts to spend on maintenance, now what it needs to spend
  • resting is not just a state of physical inactivity
  • Darwin: generations heritable features that cause organisms to have more surviving offspring will become more prevalent while features that impair reproductive success will become rarer
  • trade-offs: selection will inevitably favor whichever alternative or compromise most improves your reproductive success in your environment
  • our bodies were selected to spend enough but not too much energy on nonproductive functions including physical activity
  • humans might have evolved to be especially averse to exercise
  • our tendencies to avoid exertion are ancient instincts that make total sense from an evolutionary perspective
  • reasonable to conclude that those of us who regularly sit in chairs with backrests have weak back muscles that lack endurance — chair dependency, which is recent
  • we are more sedentary than earlier generations of Americans
  • we elevate our heart rates to moderate levels between half and one tenth as much as nonindustrial people
  • inflammation describes how the immune system first reacts after it detects a harmful pathogen, something noxious, or a damaged tissue
  • regular movement helps prevent chronic inflammation by keeping down postprandial levels of fat and sugar
  • more time you spend in a chair, higher risk of chronic illness linked to inflammation
  • standing desks have yet to be proven to offer substantial health benefits
  • leisure time sitting best predicts mortality
  • slouching has not been proven to cause back pain, no good evidence that people who sit longer are more likely to have back pain
  • best predictor of avoiding back pain is having a strong lower back with muscles that are more resistant to fatigue
  • any creature with a brain engages in some form of sleep; sleep is mostly about the brain, to analyze information, triage memories, clean, organize, analyze more effectively when we are awake
  • brain “plumbing” system relies on sleep
  • flush out the cobwebs left behind by the day’s experiences
  • Hadza people slept less than industrialized people did; rarely napped
  • no evidence that nonindustrial populations sleep more than industrial postindustrial populations
  • little empirical evidence that average sleep duration in the industrial world has decreased in the last 50 years
  • 7 hours is the standard, norm; sleeping schedules are as variable in humans as they are in other species
  • beds, pillows and the like are recent phenomenon; until recently, infants slept with mothers all the time
  • co-sleeping helps mothers and infants sleep better, helps mothers and infants coordinate sleeping and feeding and provides a wealth of positive, nurturing interactions
  • exercise increases sleep pressure, if done earlier in the day; depresses body temp
  • regular exercise is best for sleep
  • sleeping pills are dangerous, mostly placebo
  • the more physically active we are, the better we sleep
  • Usain Bolt: high forces on legs, spent more time in the air = speed
  • humans run out of gas quickly when sprinting, terrible at turning
  • humans have mostly been slowpokes since we transitioned to bipeds
  • faster we run, more sugar we burn; max aerobic capacity we burn exclusively sugar
  • sprinters are fast-twitch dominated, sprinters have larger muscles than distance runners
  • every aspect of our bodies is the product of interactions among genes we have inherited and the environments in which we have lived
  • genes might explain about half of people’s athletic talent — born and made
  • failed to identify a gene with a big effect
  • occasional HIIT makes us stronger and faster but also fitter and healthier
  • hunter gatherers are lean and modestly strong but not brawny
  • strength declined at lower rates as they got older, reflecting the fact that they stayed physically active throughout life
  • strength is how much force I produce; power is how rapidly I produce it
  • apes in the wild are mostly peaceable
  • adult chimps are no more than a third stronger than humans
  • Neanderthals — as intelligent, highly skilled close cousins whose brains were as big as ours and with whom we share 99 percent of the same genes; muscles 10 to 15 percent larger, hence stronger, robust bones
  • soreness intentionally shreds the muscle a little, stimulate growth because of micro damage, turns on a cascade of genes; short term inflammation
  • as we age, muscle fibers typically dwindle in size and number, nerves degenerate
  • muscle mass declines, load bones less, osteoporosis
  • should lift weights 2–3 times per week
  • for most of human history, however, too much muscle was more of a cost than a benefit — not enough food, resources to survive
  • humans evolved to cooperate, use tools, solve problems creatively — not so much for speed, power, strength
  • speed and strength still matter; but we have changed the way we fight and how often
  • exponentially less violent recently, thanks to social and cultural constraints, many fostered by the Enlightenment
  • we have low levels of reactive aggression but high levels of proactive aggression compared to other animals and ape cousins
  • humans evolved from small brained apelike creatures in Africa, not from large brained ancestors in Europe
  • couldn’t survive as a hunter gatherer without being cooperative
  • increased size dimorphism, cooperation, importance of women’s roles in hunter gatherer societies means we are less aggressive since the origin of Homo
  • fighting is largely a learned skill
  • play is used to develop skills and physical capacities needed to hunt or fight as adults
  • change place in societal hierarchies, forge cooperative bonds, defuse tensions
  • sports teaches cooperation, learn to restrain reactive aggression
  • discipline, courage; crucial to proactive aggression such as warfare
  • community spirit, and lucrative
  • we are physically weaker because we evolved to fight differently
  • walking illustrates the point that we didn’t evolve to exercise, but to be active when necessary
  • bipedalism evolved as an adaptation for carrying food, foraging upright, saving energy, making and using tools, keeping cool, seeing over tall grasses, swimming, and showing off genitalia
  • natural selection favored those who walked efficiently without compromising their ability to still climb effectively; solution was bipedalism
  • we are their descendants
  • carrying loads, costs increase for human output and energy
  • taking it easy was not feasible for most mothers to be until recently
  • hunter gatherer women toting food and babies carry as much as 30 percent of their body weight
  • all in all, we not only walk less today than we used to but also carry less stuff when we walk
  • modest doses of prescribed exercise rarely cause people to spend the rest of the day as couch potatoes erasing the benefits of their exertion
  • 10,000 steps — modest goal, easy to remember, plausible
  • until recently, walking wasn’t exercise, we evolved to do it as little as possible
  • “Born to Run”: by 2M years ago, ancestor Homo erectus had evolved the necessary anatomy to run long distances in the heat in order to scavenge and hunt long before the invention of bows and arrows and other projectile weapons
  • humans are unusual in habitual running long distances in the first place; we run as efficiently per pound as horses, antelopes
  • evolved long tendons such as achilles to run
  • we have the ability to perspire profusely, which enables us to run longer distances
  • turns our body into a giant wet tongue; also lost our fur
  • convergent: evolved independently in humans and other animals adapted for running
  • until recently, hunting and scavenging were dangerous without running
  • persistence hunting: chasing, then tracking, again and again
  • hunting methods used to involve running
  • ran to make war, honor gods, impress opposite sex, have fun
  • landing on ball of foot avoids the impact force caused by landing on the heel
  • highest probability of injury are among novices radically increasing their milage, competitive speedsters, marathoners, but everyday runners in between these extremes are much less prone to problems
  • non professional runners are no more likely to develop osteoarthritis than non runners
  • running and other forms of physical activity help promote healthy cartilage and may protect against disease
  • good form = low, relaxed shoulders, slightly angled torso, flexed knee during swing, nearly flat foot at landing, no overstrike (ankle bends at knee)
  • bare feet provide sensory feedback that is dampened in a shoe
  • regular physical activity slows the aging process and helps prolong life
  • foragers who survive first few years of infancy most likely to live to be 68–78
  • humans were selected to live longer and become generous, useful grandparents — grandmother hypothesis; play especially important roles
  • human health and and longevity are extended by and for physical activity
  • old age in the Stone Age meant plenty of walking, digging, carrying, other forms of activity
  • low levels of inflammation that last for months or years slowly attack our bodies
  • natural selection becomes weaker as we age
  • older we get, less selection cares about fighting the accumulation of wear and tear that comes with age
  • exercise may make things better than before (allostasis)
  • physically active people tend to have lower baseline levels of inflammation
  • selection favors people who allocate enough but not too much energy to produce antioxidants, ramp up immune system, enlarging and repairing muscles, mending bodies
  • unhealthy lifestyle affects morbidity twice as much as mortality
  • genes help load the gun, environment pulls the trigger in terms of chronic diseases
  • libertarian paternalism: companies, governments and other institutions should help us act in our own best self-interest while respective our freedom of choice
  • nudges over coercion, incentives
  • some of us evolved to want to exercise less
  • for the first time in history, wealthier people get more physical activity than the working poor
  • because exercise by definition isn’t necessary, we mostly do it for emotional or physical rewards
  • nudges influence our behaviors without force, without limiting our choices, and without shifting our economic incentives
  • shoves are more drastic, unobjectionable because you do them to yourself voluntarily, but they are more forceful than nudges
  • children who get more physical activity learn more and are smarter, happier, and less prone to depression and other mood disorders
  • half an hour of vigorous exercise and an hour of moderate exercise confer the same benefit
  • more exercise is better, but eventually it tails off
  • little solid evidence that extreme levels of exercise are either harmful or additionally healthy
  • apart from arrhythmias, no evidence that a big, strong heart poses any health risks
  • fundamental challenge of aerobic activity is to deliver more oxygen at a faster rate to muscles and other organs, this demand stimulates the chambers of the heart to grow strong, more capacious, and more elastic
  • HIIT = rapid, dramatic benefits
  • 18th century, it was fashionable to lift church bells that were silenced (made “dumb”) by having their clappers removed, hence the term dumbbells
  • evolved to spend energy on exercise primarily out of necessity and for other social reasons and otherwise sensibly reserve scarce calories for the chief thing natural selection cares about: reproductive success
  • weight loss from exercise is slower and more gradual than weight loss from dieting
  • gamble on being unfit and lean vs. fit and fat
  • cardio is better than weights for obesity
  • exercise + diet = unclogging the drain flushing out the pipes (especially for insulin resistance)
  • blood flows more rapidly through arteries, protects against high BP
  • indispensable because the cardiovascular system never evolved to develop capacity and maintain itself in the absence of demand
  • requires heart to pump high volumes of blood to every corner of the body, stimulating beneficial responses that keep blood pressure low and the heart strong
  • exercise increases immune system’s capacities
  • if you are fighting an infection, high levels of exercise are inadvisable
  • running does not cause higher rates of osteoarthritis and may sometimes be protective
  • high levels of physical activity divert energy from cancerous cells
  • can lower risk of Alzheimer’s
  • lower mental health issues
  • improves brain structure, chemistry, enhances electrical activity
  • make exercise necessary and fun, do mostly cardio but also some weights, some is better than none, keep it up as you age

I love books, I have a ton of them, and I take notes on all of them. I wanted to share all that I have learned and will continue to learn. I hope you enjoy.