For 2.4 million years – about 84,000 generations — the human body has evolved into an optimized machine that exists for one simple, all-consuming dual purpose: survive and reproduce.
Survival requires oxygen, water, food, and sleep – in that order. For about the first 83,992 generations, the process of eating was extremely difficult. To compensate for the challenges they faced, human bodies developed both externally and internally. Every neuron that fires in the brain, every neurotransmitter and hormone released, and every impulse behind every heartbeat has been intended, for millennia, to ensure that humans are living the life of an extremely focused, resilient, and capable eater.
The human body is not the only object of evolution from the last 2.4 million years. The environment has changed so quickly and so drastically from that of humankind’s ancestors that most humans now live in a state of constant misalignment. The extreme majority of the human race is no longer living up to the potential of the human body.
Bodies conditioned for thousands of generations to chase food are now having an understandably difficult time adjusting to the age of food delivery. An armada of conflicting toxins and synthetic nutrients now overwhelm digestive systems that took centuries to optimize metabolism and storage of life-sustaining complex chemicals from predictable, natural sources. Minimal levels of physical activity disrupt nervous systems attuned to supporting survival and procreation.
In 2011, an international study conducted by researchers from the University of Maryland, the Queensland School of Medicine, and Colorado State University reached the following conclusion:
“A large proportion of the health woes beleaguering modern cultures are because of daily physical activity patterns that are profoundly different from those for which we are genetically adapted. The ancestral natural environment in which our current genome was forged via natural selection called for a large amount of daily energy expenditure on a variety of physical movements.
Our genes that were selected for in this arduous and demanding natural milieu enabled our ancestors to survive and thrive, leading to a very vigorous lifestyle. This abrupt (by evolutionary time frames) change from a very physically demanding lifestyle in natural outdoor settings to an inactive indoor lifestyle is at the origin of many of the widespread chronic diseases that are endemic in our modern society.”
Human bodies are breaking down earlier and with more severity than they should be. People are aging faster, feeling worse, and having less impact on the world. “The logical answer,” the researchers go on to explain, “is to replicate the native human activity pattern to the extent that this is achievable and practical.”
Dr. Lazarus’s solution: 3 simple habits
Play often, move frequently, and use resistance occasionally to exhaustion. Consider walking and hiking often, performing high intensity movements, and adding strength sessions intermittently throughout the week. “Achievable” and “practical” mean different things for different people. Health is personal, and it should be treated as such.
1. Play often
Recreation is extremely important and something to make time for. Play is a natural part of human existence, and playing is a reminder that life should be enjoyed. Making time for recreation helps produce high quality of life and serves as a method of self-expression.
2. Move frequently
Modern humanity needs to embrace “exercising like a hunter-gatherer” to reclaim its evolutionary roots and avoid the pitfalls inherent in their rejection of optimal physical activity.
Researchers from a 2011 Progress In Cardiovascular Diseases paper said:
“In comparison with the millennial pace of genetic evolution, human technological and social evolution has occurred at light speed. This incongruence has left us genetically adapted for the demands of life as a forager in the wild despite the fact that we are living in a high-tech, sedentary, overfed, emotionally-stressed 21st century world. The instinctive solution to this conundrum is to replicate the [physical activity patterns] of our Stone Age hunter gatherer ancestors.” 
Anthropologist Kim Hill, PhD, was a source for this study. Hill spent decades living with some of the few remaining hunter-gatherer tribes on Earth. What he found is remarkably practical and immediately adoptable: hunter-gatherers run every day but not always at a high speed.
According to Hill, 10 kilometers (6.2 miles) was the average for one of the more aggressive tribes he lived with. Their average speed was around 3 kilometers per hour (about 1.1 miles per hour) with intermittent bursts of sprinting whenever prey was near.
Running 6 miles a day may seem like a lot, but the pace is not remarkably fast. While there is no “average” mile time for a typical adult, most experts agree that 7-10 minutes should be an achievable pace for a reasonably healthy person. A consistent pace with a 10-15 second wind sprint at the end of every mile is plausible and effective.
3. Use resistance to exhaustion
In the course of a single day, human ancestors were hunting and battling prey, carrying heavy materials, digging, sharpening, and dancing – all while expending consistent cardiovascular effort. The genetics of modern humanity rewards and recognizes this multi-faceted approach to exercise.
According to the 2011 study:
“Beginning at age 5 or 6 years until they were debilitated from old age or illness, hunter-gatherers would have done a range of [physical activity] each day; and they would, when possible, alternate difficult days with easier days. Their regimens called for physical efforts that developed CV and pulmonary endurance, flexibility, and strength, thereby conferring multifaceted fitness upon them. These highly variable routines of PA would have also improved their resiliency and reduced the likelihood injury, allowing them to forage and hunt with fewer major interruptions because of incapacitation.” 
The hunter-gatherer lifestyle reinforces and strengthens what the functional medicine community refers to as “functional human movements.”
The human body is a tool designed to respond to the rhythms of exhausted hunter-gathers. It was built and refined over millions of years to achieve very specific outcomes. The best exercises improve human function and efficiency. Dr. Lazarus recommends that for daily application, people should plan on doing at least one heavy day of functionally relevant exercises followed by a day of light activity.
Intentionally keeping the body on its guard through muscle confusion, intermittent intensity, and purposefully inconsistent workouts is the key to creating a resilient frame.
Fuel like a machine
Researchers from the 2011 study wrote:
“When energies eaten regularly outweigh energies expended, the excess energy is stored as fat tissue.” 
There are other important components of establishing optimal body composition which include the hormones leptin, insulin, and adiponectin as well as the diversity of the microbiome. The human body is a carefully calibrated machine intended to support its own ongoing survival.
When humans move, their bodies note the movement and make metabolic adjustments accordingly to provide energy. Brief, intense, interval exercise activates AMPK and MAPK signaling and increases the expression of PGC-1 in human skeletal muscle.  This facilitates metabolic remodeling, including mitochondrial biogenesis and an increased capacity for glucose and fatty acid oxidation. This is a key mechanism that facilitates metabolic flexibility.
During rest, hormones and metabolic signaling adjust to store energy as fat. The problem in modern humanity, however, is that the body does not use the stored energy. Metabolic outputs are no longer connected to the caloric inputs of food. From the 2011 study:
“Excess adipose tissue [fat], particularly that is stored intra-abdominally, is closely linked to many of the most common and pernicious chronic diseases in our culture. More than of every American adults are overweight or obese; CV disease remains the leading cause of death, lifetime risk of hypertension is 90%, and both type 2 diabetes mellitus and Alzheimer disease are on steeply rising trajectories. This pervasive disconnect between energies eaten and energies burned is an essential factor in these growing epidemics.” 
Even small changes can add up to major results over time. Adopting these basic lifestyle changes will reform a commitment to the covenant human ancestors forged with human bodies 84,000 generations in the past.
WholisticMatters would like to acknowledge Ryan Lazarus, MSc, CNS, IFMCP, DC, for his contributions to the content of this article.