Your Personal Paleo Code: The 3-Step Plan to Lose Weight, Reverse Disease, and Stay Fit and Healthy for Life (23 page)

Complete the quiz below and use the answer key to determine your movement score.

I sit fewer than five hours per day.

Points
: 2

I get at least thirty minutes of moderate to vigorous physical activity each day.

Points
: 2

I walk or bike to work.

Points
: 2

I do activities to increase muscle strength, such as lifting weights or calisthenics, once a week or more.

Points
: 1

I do activities to improve flexibility, such as stretching or yoga, once a week or more.

Points
: 1

I use a standing desk at work or spend several hours standing daily.

Points
: 2

I typically walk at least eight thousand steps per day (around four miles).

Points
: 3

I do not have any injuries or health conditions or symptoms that restrict my ability to exercise (such as asthma, chest pain, or fatigue).

Points
: 1

I enjoy being physically active.

Points
: 1

I watch fewer than two hours of television per day.

Points
: 1

TOTAL

Total Points
: 6+

What Your Points Mean
: You are likely getting adequate and healthy levels of physical activity.

Your Personal Paleo Code
: Complete the
Your Personal Paleo Code
3-Step program. No additional personalization is required.

Total Points
: 3–5

What Your Points Mean
: You may benefit from incorporating additional movement into your day.

Your Personal Paleo Code
: Complete the
Your Personal Paleo Code
3-Step program and add the recommendations in this chapter.

Total Points
: 0–2

What Your Points Mean
: You are likely getting an inadequate amount of physical activity.

Your Personal Paleo Code
: Complete both steps above. This should be a major focus for you, and ignoring this area may stand in the way of improvement elsewhere.

Anthropological research suggests that our ancestors sprinted, jogged, climbed, carried, and jumped intermittently throughout the day. They walked an average of six miles and ran an average of one-half to one mile per day. Women were as active as men; although they rarely took part in large-game hunting, they spent hours walking to and from sources of food, water, and wood, and they carried their children (whom they breast-fed for up to four years!) for extended distances. Our ancestors also alternated strenuous and demanding days with days of rest. This instinctual response protected them from injury and fatigue, which in turn improved their chances of survival.

Contemporary hunter-gatherers are also active. Studies show that they walk an average of ten thousand steps (about five miles) per day, with frequent bouts of more intense activity. Anthropologist Kim Hill spent thirty years living with and studying the Ache hunter-gatherers of Paraguay. His GPS data indicated that they covered more than six miles a day on average while they hunted, running in hot pursuit of their quarry for half a mile to a mile, all while “ducking under low branches and vines about once every 20 seconds all day long, and climbing over fallen trees, moving through tangled thorns, etc.” Closer to home, contemporary Amish people who have retained their traditional ways take between fourteen thousand and eighteen thousand steps per day. One way of measuring an individual’s fitness is the VO
₂
max, the volume of oxygen that can be consumed while exercising at maximum capacity (VO
₂
max is measured in milliliters of oxygen per kilogram of body weight per minute). Today, the average sedentary person has a VO
₂
max of 35 ml/kg/min, and the average elite endurance athlete has one around 70 ml/kg/min. The estimated VO
₂
max in modern hunter-gatherers is 52, which places them in the excellent-to-superior fitness category; it’s likely our ancestors were equally fit. In other words, if we want to get and stay highly physically fit, we can move more like our ancestors.

Many concepts in this chapter were inspired by the Enduring Mover framework created by Dan Pardi, a researcher on human behavior and the CEO of Dan’s Plan. As Enduring Movers, we maintain optimal health and fitness by incorporating both low-and high-intensity activity
into our daily lives, just as our ancestors did. I’ll have more to say about the Enduring Mover framework and Dan’s Plan later in the chapter.

In most Western societies, people were highly physically active until—you probably guessed it—the Industrial Revolution. In the 1800s, approximately 90 percent of jobs in America required manual labor; today, only 2 percent do. Now, thanks to dramatic changes in the way we live, communicate, travel, use technology, and get and consume our food, the typical American adult walks only about 5,900 to 6,900 steps per day.

Simply put, we’ve become a nation of sitters, whether we’re working at our computers, watching TV, playing video games, or commuting. The typical U.S. adult is now sedentary for 60 percent of his or her waking hours and sits for an average of six hours (and often much more, in the case of those who work primarily on computers). A sedentary office worker expends only ten calories per pound each day, down from the hunter-gatherer’s average of forty-three to fifty-five calories per pound per day.

We weren’t born to sit all day. We’re genetically designed to be physically active. All this increased sitting and decreased physical activity has a profound, negative effect on almost every aspect of human health, from the cardiovascular and pulmonary systems to the immune system. In fact, a whole new subfield, called sedentary physiology, has evolved to address the health risks of being too sedentary. Here are a few specific ways being sedentary harms us:

Up to two-thirds of professional cyclists, who spend long hours in a seated position, have lower levels of bone mass, studies have shown. Both humans and animals experience dramatic reductions in bone mass following spinal-cord injuries, long-term bed rest, or time in zero gravity. After just twelve weeks of bed rest, healthy men and women experienced reductions in bone-mineral density of 1 to 4 percent. What’s more, studies suggest that vigorous exercise alone isn’t enough to prevent the changes in bone metabolism caused by too much sedentary behavior.

Although the data in this area isn’t as robust as it is with metabolic and bone health, initial findings suggest that sedentary behavior has harmful effects on the vascular system. Just five days of bed rest can increase blood pressure and decrease arterial diameter. Other studies have found that after two months of bed rest, subjects had decreased blood flow and increased damage to the cells in the fragile lining of the blood vessels.

In an Australian study that followed participants over a six-and-a-half-year period, researchers found that high levels of TV time were significantly associated with increased risk of death from heart disease as well as all other causes. Each hour of TV daily was associated with an 11 percent and 18 percent increase in all-cause and cardiovascular mortality, respectively. By contrast, those who watched less than two hours of TV a day had an 80 percent lower risk of death from cardiovascular disease and a 46 percent lower risk of death from all causes when compared to those who watched more than four hours. These associations were independent of exercise and traditional risk factors such as smoking, blood pressure, cholesterol levels, waist circumference, and diet.

A U.S. study based on twenty-one years of follow-up of 7,700 men found that those who reported spending more than ten hours a week sitting in automobiles or more than twenty-three hours a week of combined TV and automobile time had an 82 percent and 64 percent greater risk of death from cardiovascular disease compared to those who spent less than
four hours a week in cars or less than eleven hours a week of combined sedentary time, respectively. Regular physical activity is one of the best predictors of long-term health and survival in large, observational studies. In fact, your fitness level (as measured by performance on a treadmill exercise test) has been shown to be a better predictor of how and when you’ll die than age, body mass index, or even cardiovascular risk factors.

In other words, if you want to live longer, you have to be physically active on a regular basis.

And if you want a better quality of life, physical activity’s the answer too. Adults who exercise report higher quality of life, and studies have shown that physical activity improves cognitive function in the elderly. These benefits are evident from the earliest years; physically active children report greater body satisfaction and self-esteem than their sedentary peers. Finally, getting adequate exercise during the day promotes deeper and more restful sleep at night and reduces pre-sleep anxiety and insomnia.

Maybe you’re thinking,
Okay, I sit a lot—but I also work out a lot, so I’m good.
Here’s the shocker: too much sitting and sedentary time is harmful
even if you’re getting enough exercise.
This means you could be meeting the recommended government guidelines for exercise (that is, thirty minutes of moderate to vigorous activity five days a week) but still be at high risk of heart disease if you sit for long periods each day. In fact, a large study involving over one hundred thousand U.S. adults found that those who sat for more than six hours a day had up to a 40 percent greater risk of death over the next fifteen years than those who sat for less than three hours a day
regardless of whether the participants exercised.
Canadians who reported spending the majority of the day sitting had an increased risk of death compared to those who reported less time sitting. As with the American study, this association was apparent even among those who exercised regularly. Perhaps you’re one of these active couch potatoes. If
you work in an office, commute by car, and watch a few hours of TV each night, it’s not difficult to see how you could spend the vast majority of your waking hours sitting on your butt. Imagine the following hypothetical day:

If you did this routine five days a week, you’d meet the typical guidelines for exercise (at least one hundred and fifty minutes of moderate exercise a week), but you’d also be sitting for at least twelve hours a day.

The evidence clearly indicates that sitting too much is harmful in itself and that exercise alone isn’t enough to reverse the harmful effects. But there are other problems with looking at exercise as solely an intervention.

In an effort to overcome inactivity when they’re not exercising, some people are overtraining. Exercise is a stressor. Not all stress is harmful; in the right dose, it can cause a positive adaptation and better equip you to face that stressor in the future. This is referred to as hormesis. Weightlifting is a great example of the hormetic effects of stress. When you lift weights, you stress the muscles, and this causes them to get stronger.

However, when stress exceeds your capacity to adapt, it stops having a beneficial, hormetic effect and begins to cause damage. (See the section “Are You Overtraining?”) Just as we didn’t evolve to sit so much, we’re not adapted to perform excessive amounts of exercise. A large and growing body of evidence has demonstrated that excessive exercise, such as marathons, ultra-marathons, full-distance triathlons, and very long-
distance bicycle rides, is associated with damage to the heart, muscles, and joints. Overtraining has been associated with increased injury, oxidative damage, inflammation, and cognitive decline, as well as with decreased immune function, fat metabolism, and cardiovascular health. Consider the following: