Back to the Future: A Paleolithic Exercise Program for the 21st Century

There is no question that modern-day life has virtually eliminated the requirement to be physically active. Unlike our Paleolithic ancestors, our survival is not dependent upon our ability to hunt, gather or grow our own food or even build our necessary shelters. With these advances, of course, have come a serious downside—a sedentary, indoor lifestyle that is at the origin of many of the once-rare chronic diseases that are now all too common. Some have suggested that replicating the activity patterns of indigenous humans—to the extent that this is possible and practically achievable in today’s society—could be an effective way to reduce the incidence of these diseases. This article examines this premise and offers practical recommendations for exercise frequency, intensity, duration and mode for realigning our daily physical activities with the classic levels expected within our unchanged Paleolithic genome.
A Genetic Predisposition for Physical Work
For most of the past 2.4 million years, approximately 84,000 generations of our ancestors lived a lifestyle comprised of hunting and gathering (O’Keefe et al., 2011). The existence of hunter-gatherers was characterized by foraging and hunting for food, producing water, building and maintaining clothing and shelter, escaping from predators and enjoying social interaction. Accordingly, over time the human genetic profile gradually adapted through natural selection for individuals to survive and thrive in an environmental climate that demanded large amounts of regular physical work. More recently, from an evolutionary perspective, there have been rapid improvements in technology that have brought about marked reductions in the physical work required as part of daily life. In fact, technological advancements over the past 10,000 years—a period marked by the Agricultural Revolution (the past 350 generations), Industrial Revolution (the past seven generations), and in particular the Digital Age (the past two generations)—have resulted in the elimination of most previously required physical activities (O’Keefe et al., 2010a). For instance, in most Westernized countries, the need to spend a meaningful energy expenditure on obtaining food has become virtually obsolete. Despite the quantum leap in technology during this 10,000-year period, our genetic profile has remained largely unchanged. In reality, it has been estimated that our genome is 98.4 percent similar to what it would have been just prior to the Agricultural Revolution (Eaton, Konner and Shostak, 1988).

Discordance Hypothesis and its
Clinical Significance

The shortfall between physical-activity levels anticipated by our genetic profile for normal metabolic function, and that which is actually incurred (a premise referred to as the discordance hypothesis), has created an environment ideal for the manifestation of various chronic diseases. In recent times, particularly over the past 100 years, there has been a meteoric and widespread rise in the prevalence of obesity, type 2 diabetes and cardiovascular disease. These conditions, nonexistent-to-rare in the ancient world, are now common throughout modern society (O’Keefe et al., 2010b). Every year since 1900, with the exception of 1918 when there was a worldwide influenza epidemic, cardiovascular disease (CVD) has been the most common cause of death. According to the American Heart Association, 82.6 million American adults (more than one in three) have one or more types of CVD (Lloyd-Jones et al., 2007). Although the prevalence of CVD-related deaths has declined since the 1980s, it remains the leading cause of death in the United States (Roger et al., 2011). In 2007, CVD claimed 813,804 lives, with nearly half (49.9 percent) attributable to coronary artery disease.
Since the advent of the digital age two generations ago, there has been a particularly alarming increase in the prevalence of obesity and type 2 diabetes. For example, in the time period between 1960 and 2000, the prevalence of U.S. adults with class I obesity (BMI between 30.0 and 34.0 kg/m²) increased, on average, by 2.5 percent per year (Booth et al., 2000). 2009 data show that only one state’s population (Colorado) had a prevalence of obesity of less than 20 percent. Thirty-four states were equal to or greater than 25 percent and nine of these (Alabama, Arkansas, Kentucky, Louisiana, Mississippi, Missouri, Oklahoma, Tennessee and West Virginia) had a prevalence equal to or greater than 30 percent (Centers for Disease Control and Prevention, 2012). It has been estimated that nearly 300,000 deaths per year can be attributed to obesity (Booth et al., 2000). In a similar manner to obesity, the prevalence of type 2 diabetes has skyrocketed throughout the digital age. A sixfold increased prevalence of type 2 diabetes occurred between 1958 and 1993. To date, 25.4 million American adults (11.5 percent of the U.S. adult population) have diabetes mellitus. The American Diabetes Association estimates that nearly 200,000 deaths per year are attributable to type 2 diabetes; this number is expected to rise in the future (Booth et al., 2000).

Unfortunately, the elimination of both the need for, and the performance of, regular movement has left our bodies confused and vulnerable to chronic disease (see sidebar, “Discordance Hypothesis and its Clinical Significance”).
What is the solution? Although many approaches are likely necessary, taking a closer look at the physical-activity patterns of our Paleolithic ancestors may yield valuable understanding into what is needed to restore metabolic health. In other words, an examination of our past might provide the answer to a better future.

The Paleolithic Exercise Regimen: Life in the Wilderness

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Back to the Future: A Paleolithic Exercise Program for the 21st Century