Exercised Quotes

“Although tendons are unnecessary for walking, they function as springs during running.”
― Daniel E. Lieberman, Exercised: The Science of Physical Activity, Rest and Health

“Even more excitingly, we could see that gorillas, chimpanzees, and early hominins lack a nuchal ligament, but humans and fossil species from the genus Homo had them. If the nuchal ligament was an adaptation to stabilize the head during running, here was evidence that millions of years ago humans had been selected to run.”
― Daniel E. Lieberman, Exercised: The Science of Physical Activity, Rest and Health

“According to Wrangham, humans differ from other animals, especially our ape cousins, in having exceedingly low levels of reactive aggression but much higher levels of proactive aggression. We correspond to Rousseau in terms of reactive aggression and to Hobbes in terms of proactive aggression.”
― Daniel E. Lieberman, Exercised: The Science of Physical Activity, Rest and Health

“We traded brawn for brains. Instead of relying on speed, power, and strength, humans evolved to cooperate, use tools, and solve problems creatively.”
― Daniel E. Lieberman, Exercised: The Science of Physical Activity, Rest and Health

“Done properly and not in excess, strength training also helps prevent injuries.57 Finally and importantly, warding off sarcopenia in old age helps prevent depression and other mental health conditions.”
― Daniel E. Lieberman, Exercised: The Science of Physical Activity, Rest and Health

“Strength is how much force I can produce; power is how rapidly I produce it.”
― Daniel E. Lieberman, Exercised: The Science of Physical Activity, Rest and Health

“Among other benefits, recovery from exercise gradually lowers basal cortisol and epinephrine levels, depresses body temperature, and even helps re-sync the circadian clock.”
― Daniel E. Lieberman, Exercised: The Science of Physical Activity, Rest and Health

“The Maori of New Zealand, for example, used to sleep communally in longhouses and still sleep this way at funerals to accompany a corpse on its journey from this world to the next.38 The Asabano of New Guinea never let a stranger sleep alone because of the dangers of nighttime witchcraft, and the Warlpiri of Central Australia sleep under the stars in rows whose order is determined by strict social rules.39 In”
― Daniel E. Lieberman, Exercised: The Science of Physical Activity, Rest and Health

“Instead, the best predictor of avoiding back pain is having a strong lower back with muscles that are more resistant to fatigue; in turn, people with strong, fatigue-resistant backs are more likely to have better posture.71”
― Daniel E. Lieberman, Exercised: The Science of Physical Activity, Rest and Health

“In fact, people who rarely sat for more than twelve minutes at a time had lower death rates, and those who tended to sit for half an hour or longer at a stretch without getting up had especially high death rates.”
― Daniel E. Lieberman, Exercised: The Science of Physical Activity, Rest and Health

“they were astonished to discover that muscles regulate inflammation during bouts of moderate to intense physical activity similarly to the way the immune system mounts an inflammatory response to an infection or a wound.”
― Daniel E. Lieberman, Exercised: The Science of Physical Activity, Rest and Health

“Every hour spent resting comfortably in a chair is an hour not spent exercising or actively doing things. The second concern is that long periods of uninterrupted inactivity harmfully elevate levels of sugar and fat in the bloodstream. Third and most alarmingly, hours of sitting may trigger our immune systems to attack our bodies through a process known as inflammation. Don’t panic, but as you sit comfortably reading this, your body may be on fire. On”
― Daniel E. Lieberman, Exercised: The Science of Physical Activity, Rest and Health

“In a delightfully comprehensive study, the anthropologist Gordon Hewes documented more than a hundred postures that humans from 480 different cultures adopt when they sit without a chair.”
― Daniel E. Lieberman, Exercised: The Science of Physical Activity, Rest and Health

“But that doesn’t mean genes don’t play an important role in disease. Genetic variations influence plenty of chronic diseases such as coronary artery disease, heart arrhythmias, type 2 diabetes, inflammatory bowel disease, and Alzheimer’s.65 In these and other cases, genes help load the gun, but environment pulls the trigger.”
― Daniel E. Lieberman, Exercised: The Science of Physical Activity, Rest and Health

“The pay is good and I can walk to work. —John F. Kennedy”
― Daniel E. Lieberman, Exercised: Why Something We Never Evolved to Do Is Healthy and Rewarding

“Finally, a study of more than one hundred thousand nurses (two-thirds of them women) that controlled for smoking, weight, alcohol consumption, sex, and age found an inverse dose-response relationship between levels of physical activity and the risk of pneumonia, with a more than 30 percent reduction between the women (but not men) who were most and least active.55 Despite these encouraging findings, not all studies report lower RTI rates among exercisers, in part because these sorts of trials are difficult to conduct.”
― Daniel E. Lieberman, Exercised: Why Something We Never Evolved to Do Is Healthy and Rewarding

“It is also unclear why physical inactivity might be a mismatch for the immune system apart from the generally negative effects of sedentariness on overall health and levels of stress (which, as we have seen, depresses the immune system). One possibility is that because heading off to the bush to hunt and gather potentially made our ancestors more likely to encounter pathogens, our immune systems evolved to compensate by ramping up our defenses when we are active. A related possible explanation stems from the stingy way our bodies use calories. The fatigue we experience when fighting a cold is a reminder that the immune system is often energetically costly. As a result, maybe our immune systems evolved to be less vigilant when they are less needed. For hunter-gatherers, unlike most industrial people, those times might have been when they were less physically active and thus less likely to be exposed to pathogens.”
― Daniel E. Lieberman, Exercised: Why Something We Never Evolved to Do Is Healthy and Rewarding

“To explore how physical activity helps but doesn’t entirely prevent cardiovascular diseases, let’s return to the trinity of intertwined factors that are the root causes of the problem: high cholesterol, high blood pressure, and inflammation. Cholesterol. A cholesterol test usually measures the levels of three molecules in your blood. The first is low-density lipoprotein (LDL), often termed bad cholesterol. Your liver produces these balloon-like molecules to transport fats and cholesterol throughout your bloodstream, but some LDLs have a harmful tendency to burrow into the walls of arteries, especially when blood pressure is high. These intrusions cause an inflammatory reaction that generates plaques. The second type of cholesterol is high-density lipoprotein (HDL), sometimes called good cholesterol, because these molecules scavenge and return LDLs back to the liver. The third type are triglycerides, fat molecules that are floating freely in the bloodstream and a signpost for metabolic syndrome. To make a long story short, diets rich in sugar and saturated fats contribute to cardiovascular disease because they promote high levels of plaque-forming LDLs. Conversely, physical activity helps prevent cardiovascular disease by lowering triglycerides, raising HDL levels, and to a lesser degree lowering LDL. Blood pressure. A blood pressure test gives you two readings: the higher (systolic) number is the pressure your heart’s main chamber overcomes when it squeezes blood throughout your body; the lower (diastolic) number is the pressure your heart experiences as its main chamber fills with blood. By convention high blood pressure is a reading greater than 130/90 or 140/90. Blood pressures above these values are concerning because, unabated, they damage the walls of arteries, making them vulnerable to invasion by plaque-inducing LDLs. As we already saw, once plaques start to form, blood pressure can rise, potentially stimulating yet more plaques. Chronically high blood pressure also strains the heart, causing it to thicken abnormally and weaken. By forcing more blood to flow more rapidly through arteries, physical activity stimulates the generation of new arteries throughout the body and helps keep existing arteries supple, protecting against high blood pressure. Inflammation. Plaques don’t form out of the blue but instead occur when white blood cells in the bloodstream react to the inflammation caused by LDLs and high blood pressure. Chronic inflammation also increases one’s likelihood of developing plaques from high cholesterol and blood pressure.40 And, as we have previously seen, while inflammation is caused by factors such as obesity, junky diets, excess alcohol, and smoking, it is substantially lowered by physical activity.”
― Daniel E. Lieberman, Exercised: Why Something We Never Evolved to Do Is Healthy and Rewarding

“In the last 120 years, coronary artery disease has exploded more than two-and-a-half-fold to become a leading cause of death worldwide.38 Since Jeremy Morris’s pioneering study on London bus conductors first pointed the way, it has become indisputable that coronary artery disease is a largely preventable mismatch caused by a combination of formerly rare risk factors: high cholesterol, high blood pressure, and chronic inflammation.39 These harbingers of disease, in turn, are affected by genes but are mostly caused by the same interrelated behavioral risk factors we keep encountering: smoking, obesity, bad diets, stress, and physical inactivity.”
― Daniel E. Lieberman, Exercised: Why Something We Never Evolved to Do Is Healthy and Rewarding

“Arrhythmias are additional common causes of problems and death, and the heart can also be damaged by infections, birth defects, drugs, and faulty wiring. But atherosclerosis is by far the leading culprit, and chronically high blood pressure, hypertension, is a close second. Hypertension is a silent condition that relentlessly strains the heart, arteries, and various organs. At least 100,000 times a day, the heart forces about five liters of blood through thousands of miles of arteries that resist each squeeze, generating pressure. When we exercise, blood pressure rises temporarily, causing the heart’s muscular chambers to adapt, mostly by becoming stronger, larger, and more elastic so it can pump more blood with each stroke.30 Just as important, arteries also adapt to exercise to keep blood pressure low, primarily by expanding, multiplying, and staying elastic.31 However, when blood pressure is chronically high, the heart defends itself by developing thicker muscular walls. These thicker walls stiffen and fill with scar tissue, and eventually the heart weakens. A vicious cycle then ensues. As the heart’s ability to pump blood declines, it becomes harder to exercise and thus control high blood pressure. Blood pressure may rise as the heart progressively weakens until the failing heart cannot support or sustain a normal blood pressure. Death usually ensues. Coronary artery disease is ancient and has even been diagnosed in mummies.32 But research on nonindustrial populations provides powerful evidence that coronary artery disease and hypertension are largely evolutionary mismatches. Although many medical textbooks teach doctors that it’s normal for blood pressure to rise with age, we have known since the 1970s this is not true among hunter-gatherer populations like the San and the Hadza.33 The average blood pressure in a seventy-year-old San hunter-gatherer is 120/67, no different from a twenty-year-old. Lifelong low blood pressure also characterizes many subsistence farming populations. My colleagues Rob Shave and Aaron Baggish and I measured more than a hundred Tarahumara farmers of every age and found no difference in blood pressure between teenagers and octogenarians.34 By the same token, blood pressure can also stay normal into old age among industrialized people who eat sensibly and stay active.35”
― Daniel E. Lieberman, Exercised: Why Something We Never Evolved to Do Is Healthy and Rewarding

“The heart is essentially a muscular pump connected to an elaborate network of branching tubes. Although there are several kinds of cardiovascular disease, almost all arise from something going wrong in either the tubes or the pump. Most problems start with the tubes, primarily the arteries that carry blood from the heart to every nook and cranny of the body. Like the pipes in a building, arteries are vulnerable to getting clogged with unwanted deposits. This hardening of the arteries, termed atherosclerosis, starts with the buildup of plaque—a gloppy mixture of fat, cholesterol, and calcium—within the walls of arteries. Plaques, however, don’t simply accumulate in arteries like crud settling in a pipe. Instead, they are dynamic, changing, growing, shifting, and sometimes breaking. They develop when white blood cells in arteries trigger inflammation by reacting to damage usually caused by a combination of high blood pressure and so-called bad cholesterol that irritates the walls of the artery. In an effort to repair the damage, white blood cells produce a foamy mixture that incorporates cholesterol and other stuff and then hardens. As plaque accumulates, arteries stiffen and narrow, sometimes preventing enough blood from flowing to the tissues and organs that need it and further driving up blood pressure. One potentially lethal scenario is when plaques block an artery completely or detach and obstruct a smaller artery elsewhere. When this happens, tissues are starved of blood (also called ischemia) and die. Plaques can also cause the artery wall to dilate, weaken, and bulge (an aneurysm) or to tear apart (a rupture), which can lead to massive bleeding (a hemorrhage). Blocked and ruptured arteries create trouble anywhere in the body, but the most vulnerable locations are the narrow coronary arteries that supply the heart muscle itself. Heart attacks, caused by blocked coronary arteries, may damage the heart’s muscle, leading to less effective pumping of blood or triggering an electrical disturbance that can stop the heart altogether. Other highly vulnerable arteries are in the brain, which cause strokes when blocked by blood clots or when they rupture and bleed. To this list of more susceptible locations we should also add the retinas, kidneys, stomach, and intestines. The most extreme consequence of coronary artery disease is a heart attack, which, if one survives, leaves behind a weakened heart unable to pump blood as effectively as before, leading to heart failure.”
― Daniel E. Lieberman, Exercised: Why Something We Never Evolved to Do Is Healthy and Rewarding

“In one compelling study, Danish researchers randomized patients with type 2 diabetes into two groups: both were given advice on how to eat a healthy diet, but one group also labored through five or six 30- to 60-minute-long sessions of aerobic exercise a week plus two or three weight sessions per week. After a year, half of those who exercised were able to eliminate their diabetes medications, and another 20 percent were able to reduce their medication levels. Further, the more they exercised, the more they recovered normal function. In contrast, just one-quarter of the dieters were able to reduce their medication, and 40 percent had to increase their medication levels despite receiving excellent, standard health care.24 As we have repeatedly seen, some exercise is better than none, and more is better.”
― Daniel E. Lieberman, Exercised: Why Something We Never Evolved to Do Is Healthy and Rewarding

“Having type 2 diabetes raises a person’s risk of dying, in some cases to a small degree, in other cases substantially, but it is treatable using drugs, diet, and exercise. Although drugs help, they aren’t always necessary. Diet and exercise can sometimes allow the body to heal itself. In one dramatic test of this concept, ten overweight Australian aborigines with type 2 diabetes reversed their disease after just seven weeks of returning to an active hunting and gathering lifestyle.20 The mechanisms by which physical activity helps prevent and treat type 2 diabetes are well studied. Most basically, exercise (in conjunction with diet) can ameliorate every characteristic of metabolic syndrome including excess organ fat, high blood pressure, and high levels of blood sugar, fat, and cholesterol. In addition, exercise lowers inflammation and counteracts many of the damaging effects of stress. And most remarkably, exercise can reverse insulin resistance by restoring blocked insulin receptors and causing muscle cells to produce more of the transporter molecules that shuttle sugar out of the bloodstream.21 The effect is akin to unclogging a drain and flushing out the pipes. Altogether, by simultaneously improving the delivery, transport, and use of blood sugar, exercise can resuscitate a once resistant muscle cell to suck up as much as fiftyfold more molecules of blood sugar. No drug is so potent.”
― Daniel E. Lieberman, Exercised: Why Something We Never Evolved to Do Is Healthy and Rewarding

“How Much and What Kind of Exercise Are Best? This one is easy: cardio is better than weights for obesity. As we will see later, weights help counteract some of the metabolic consequences of obesity, but cardio is better for preventing and reversing excess weight. One randomized control study that compared the effects of cardio and weights on overweight and obese adults found that individuals prescribed just weights barely lost any body fat but those prescribed twelve miles a week of running lost substantial amounts of fat, especially harmful organ fat.12 How much the intensity of cardio matters for weight loss, however, is up for debate. Although individuals vary widely in their responses, higher-intensity activities generally burn more calories than lower-intensity activities, but they are also harder to maintain for long and thus sometimes end up consuming less total energy.13 What matters most is probably cumulative dose. A hundred and fifty minutes of walking a week is probably not enough to lose much weight.”
― Daniel E. Lieberman, Exercised: Why Something We Never Evolved to Do Is Healthy and Rewarding

“While overweight people who exercise and are physically fit lessen their risk of chronic disease, if you must choose between being fit and fat or unfit and lean, the evidence overwhelmingly indicates you should gamble on being unfit and lean.10 One of the largest efforts to tease apart the independent effects of physical inactivity and weight is the Nurses’ Health Study, a prodigious undertaking begun in 1976 that has tracked the habits, health, and deaths of more than 100,000 nurses who volunteered to share their life and death experiences with Harvard researchers. Among the many lessons learned is that nurses of the same weight who are physically active have mortality rates (deaths per year) about 50 percent lower than those who are inactive, while nurses who are similarly active but obese have 90 percent higher mortality rates than those who are lean.11 If so, obesity has nearly twice the effect on death rates as physical inactivity. Even better is to avoid both risk factors: nurses who are lean and fit have 2.4 times lower mortality rates than those who are obese and unfit. All in all, being active doesn’t cancel out the higher risk of death associated with obesity, but being active is still beneficial if one is obese. This is an important message because so many people struggle to lose weight but can still manage to exercise. In doing so, they lessen or counteract many harmful consequences of obesity such as chronic inflammation.”
― Daniel E. Lieberman, Exercised: Why Something We Never Evolved to Do Is Healthy and Rewarding

“The most common arguments against using exercise to control weight are that calories from diet dwarf those spent on physical activity and that exercise increases hunger and fatigue, thus supposedly causing us to compensate by eating more and becoming couch potatoes after we exercise. A two-mile walk burns about 100 more calories than sitting, but that refreshing Coca-Cola afterward contains 140 calories. However, studies show that people who exercise more don’t necessarily compensate by eating more and they usually don’t become less active for the rest of the day.5 It is untrue you can’t lose weight by exercising. Instead, weight loss from exercise is much slower and more gradual than weight loss from dieting. Over the course of a year, walking an extra two miles a day can potentially lead to five pounds of weight loss. In addition, exercise definitely helps prevent weight regain following a diet, and likely plays a major role in preventing weight gain in the first place.6”
― Daniel E. Lieberman, Exercised: Why Something We Never Evolved to Do Is Healthy and Rewarding

“When we are in positive energy balance from consuming more calories than we expend, we convert surplus calories into fat that we store in fat cells. When we are in negative energy balance from spending more calories than we consume, we burn some of this fat. This calories-in-calories-out equation, however, is regulated by hormones, which in turn are strongly affected by diet and by other factors including psychosocial stress, the microbes in our gut, and, of course, physical activity.”
― Daniel E. Lieberman, Exercised: Why Something We Never Evolved to Do Is Healthy and Rewarding

“As we age, daily hours of minimal physical activity—typically in chairs—render us more vulnerable to a litany of chronic illnesses and disabilities that used to be rare or unknown such as heart disease, hypertension, many cancers, osteoporosis, osteoarthritis, and Alzheimer’s. It is commonly assumed that these conditions are the inevitable by-products of more of us living to be older. But this is not entirely true. Exercise may not be an elixir, but by stimulating growth, maintenance, and repair, it can reduce our susceptibility to many of these mismatches. In this sense, exercise is medicinal. And unlike other medicines, exercise is free, has no side effects, and is sometimes fun. So to stay healthy and fit, many of us exercise.”
― Daniel E. Lieberman, Exercised: Why Something We Never Evolved to Do Is Healthy and Rewarding

“Then, in a blink of the eye, we invented the modern postindustrial world. Suddenly some of us can take it easy 24/7 in ways unimaginable to earlier generations. Instead of walking, carrying, digging, running, and throwing, we sit for most of the day in ergonomically designed chairs, stare at screens, and press buttons. The only catch is we still inherited our active ancestors’ thrifty genes that rely on physical activity to grow, maintain, and repair our bodies. Incessant sitting combined with modern diets and other novelties thus contributes to evolutionary mismatches, defined as conditions that are more common and severe today than in the past because our bodies are poorly adapted to novel environmental conditions.3 The twenty-first-century world, of course, is not without extraordinary benefits. Today, nearly seven billion of us live longer and healthier lives than most of our Stone Age forebears ever did, many of us enjoying comforts beyond the imaginations of pharaohs and emperors of yore. But just as we never evolved to cope with jet lag or guzzle gallons of soda, we never evolved to be persistently physically inactive.”
― Daniel E. Lieberman, Exercised: Why Something We Never Evolved to Do Is Healthy and Rewarding

“And so, for countless generations, our ancestors rested as much as possible but also spent many hours a day walking, carrying, and digging, and occasionally they also ran, climbed, threw, danced, and fought. Their lives were challenging, and plenty of them died young, but physical activity helped many of those who survived childhood to become active, productive grandparents.”
― Daniel E. Lieberman, Exercised: Why Something We Never Evolved to Do Is Healthy and Rewarding