The Paleo Diet for Athletes (30 page)

Calorie burn (kilocalories per hour) is based on a 176-pound man or 132-pound woman.

WHY WE ARE DESIGNED TO EXERCISE

It may seem obvious, but sometimes the obvious is rarely considered. Do you know why the Ache and, for that matter, all hunter-gatherers exercise? Before we go down this road, let’s clarify the word “exercise.” No adult hunter-gatherers in their right minds would have ever set off on a
run or repeatedly lifted a heavy stone simply to expend energy and “get exercise.” Virtually all of their movement resulted from the day’s mandatory activities: food and water procurement, shelter building, journeys, tool making, wood gathering, escape from dangers, child rearing, and social activities. Hunter-gatherers had no choice but to do physical labor of all kinds, big and small, day in and day out, for their entire lives. There were no retirements, vacations, layoffs, career changes, or labor-saving devices. Except for the very young or the very old, everyone did labor of one form or another on a regular basis.

Let’s get back to the obvious that you may never have considered. Hunter-gatherers “exercised” because they had to. They had no other choice—period! For all humans living before the agricultural revolution, energy input (food) and energy expenditure (exercise) were directly linked. If Stone Age people wanted to eat, they had to hunt, gather, forage, or fish. Now you can see what may have motivated the Ache hunters as they furiously chased that herd of peccaries hour after hour through the tropical forest in Paraguay. Whether you do a long, hard workout or none at all, food is always there for you at the end of the day. Wouldn’t it be disappointing to do your long, hard workout and come home to an empty fridge? Would an empty belly motivate you even more on the next workout (hunt) if the intensity of the exercise were directly related to the amount of food in the refrigerator?

In the modern world, we have totally obliterated the ancient evolutionary link between energy expenditure and food intake. As you lazily stroll down the grocery aisle and throw one item after another into the cart, you don’t give a single thought to “search time” or “pursuit” of your prey, as Dr. Hill graphically portrayed for us with his description of the Ache hunters. In a supermarket, the search and pursuit times are identical whether you toss a smoked ham or a head of lettuce into your cart.

The consequences of severing this primeval evolutionary connection between energy expenditure and intake are not pretty. When we eat more energy than we expend, we gain weight. And when we gain weight, our health suffers. Unless you pay no attention to printed or online news,
you know that we are in the midst of an obesity epidemic in the United States. Two-thirds of all Americans are either overweight or obese, 40 million have type 2 diabetes, and cardiovascular disease is the leading cause of death in this country. There is little doubt in my mind that none of this would be possible without the uncoupling of energy intake and expenditure that was handed to us when we deserted our ancestral hunter-gatherer way of life.

COMPARING THE LIFESTYLES OF HUNTER-GATHERERS AND MODERN ATHLETES

After reading Dr. Hill’s description of the
Ache hunters
, you probably have a pretty good feel for how their daily workout compares with yours, whether you’re a recreational athlete, an accomplished local and regional endurance athlete, or an elite athlete of national or international caliber. How would the average hunter-gatherer stack up when it comes to high-level endurance performance on race day?

First, let’s take a look at the advantages on the hunter-gatherer’s side. From the time of weaning until very old age, hunter-gatherer athletes would have done moderate to hard aerobic activity, month in and month out, for their entire lives. They would have regularly rotated hard days with easy ones, and strength activities would have commonly accompanied aerobic work. This pattern of movement would have diminished their chance of injury, so they could get up morning after morning to hunt and gather again and again.

In exercise physiology there is a well-known law stating that aerobic capacity (max VO
₂
) within an individual may increase based upon exercise frequency, intensity, and duration. Of these three factors, intensity is the most important feature in squeezing out the last bit of aerobic capacity from already trained subjects. The problem is that as intensity increases, the chances of injury and illness also increase. Hunter
gatherers were in it for the long haul. Their objectives were to obtain food day in and day out, year in and year out. Regular high-intensity exercise would have been a liability because injury and illness meant less food. On the other hand, today’s endurance athletes don’t have to worry about injuries or illness getting in the way of eating; food is always available, no matter what your condition. Accordingly, endurance athletes can take their chances with high-intensity training. As a matter of fact, high-intensity workouts (>85 percent max VO
₂
) are not an anomaly but rather a requisite to perform at the highest levels upon the world’s stage.

As we previously outlined, it is virtually impossible to exercise at >85 percent max VO
₂
for extended periods unless muscle glycogen stores are fully topped off. Without daily consumption of high glycemic load carbs, regular high-intensity workouts simply are not feasible. Since high glycemic load carbs were not on the hunter-gatherers’ menus, they could not have eked out the last 2 to 5 percent of their genetic aerobic potential by doing high-intensity workouts, as can modern athletes. On the other hand, because they ate more fat and fewer daily meals than we do, their intramuscular triglyceride stores would have been much higher, thereby allowing them to do aerobic work at moderate intensity for extended periods—just what the doctor ordered if you need to go hunting daily and high glycemic carbs don’t exist. For the modern-day endurance athlete who is solely interested in maximum performance, an alternative exists: Both can be done. You can maximize muscle glycogen and triglyceride stores by following the diet we have summarized in
Chapters 2
,
3
, and
4
and
9
.

Because the protein content of their diet was higher than ours, the concentration of the anabolic branched-chain amino acids (leucine, isoleucine, and valine) would have been much higher. As pointed out previously, these dietary amino acids promote muscle resynthesis following exercise and may also delay the onset of fatigue. Unless you are eating lots of lean meats and fish, hunter-gatherers would have had the advantage here. The high protein content of our ancestral diet meant that
another amino acid, glutamine, would also have been higher than what you get in a vegetarian diet of beans and brown rice, or simply the standard American junk-food diet. A classic symptom of overtraining in endurance athletes is low blood levels of glutamine.

The trick with glutamine is not just how much you are getting but also how much you are losing. Losing excess glutamine is just like not getting enough. If you are eating a high-carb, low-fat diet—pretty much the standard endurance-athlete fare—it is almost certain that your body will be in a slight state of net metabolic acidosis. As we have previously shown, a net acid-producing diet causes your body to excrete more and more of the muscles’ glutamine in an attempt to restore acid-base balance. The loss of muscle glutamine from an acid-yielding diet and from insufficient intake of glutamine-rich foods (lean meats, fish, and seafood) may adversely affect performance. Chalk up another advantage to hunter-gatherers.

One of the most important variables leading to athletic success is staying healthy and free of illness and colds. There is little doubt that proper nutrition is absolutely essential for optimizing your immune system. Because hunter-gatherers ate no processed foods, cereal grains, or refined sugars or oils, their intake of trace nutrients (vitamins, minerals, and phytochemicals) was way higher than what the average US citizen gets. Also, they consumed more healthful omega-3 fatty acids than most of us now do. These dietary advantages would have again allowed our hunter-gatherer ancestors to go out day after day to hunt and forage without interruption from illness. For our species, natural selection had no interest in winning a 10-K or marathon; the name of the evolutionary game was adequate calories, not maximum exercise performance.

So let’s get down to the nitty-gritty. Was there ever a hunter-gatherer who could have taken home the Olympic gold in any endurance event in the last 30 years? The answer is no. The average hunter-gatherer was clearly more fit than the average American couch potato, as we pointed out in the Introduction. Most foragers, both men and women, could have run any recreational runner into the ground. At the local and regional levels, their best athletes would have been competitive. But there
is no comparison between them and elite national and international athletes for two basic reasons.

First are the numbers. The primary determinant of aerobic capacity is maximum oxygen consumption, or max VO
₂
. If you want to be a world-class endurance athlete, you better choose your parents well, because max VO
₂
is almost entirely determined by genetics. One of the highest max VO
₂
values ever reliably recorded for an elite male athlete in the United States is about 84 milliliters per kilogram per minute (ml/kg/ min). Contrast this value to about 40 ml/kg/min for the average American male. So what happens if the 40 ml/kg/min guy wants to become world class and sets off upon an incredibly intense training program for years and years? Does he have a chance of getting to 84 ml/kg/min? Not even close! Max VO
₂
can increase by about 10 to 15 percent in the best of all worlds, but no more. In the United States, we now have more than 300 million residents. Compare this with the fewer than 1,000 Ache hunter-gatherers that Dr. Hill accompanied. If only one person out of 1,000 has a genetically determined max VO
₂
of greater than 70 ml/kg/ min, then in the US population, there will be 30,000 people who have the genetic potential to perform at extremely high aerobic capacities. Among the Ache hunter-gatherers, only one person in their entire population will have this genetic capacity.

Hunter-gatherers wouldn’t stand a chance against Olympian endurance athletes, not only because of the numbers game but also because they were limited to low-octane fuel. Intramuscular triglyceride is a great energy source for moderate to hard exercise lasting for hours, but it can’t hold a candle to glycogen when it comes to high-level exertion at 85 percent or greater of the VO
₂
required to make Olympic champions. Because hunter-gatherers ate less carbohydrate and more fat, along with fewer daily meals, their intramuscular triglyceride stores would have been higher than ours. But they also ate no high glycemic load carbs (except for occasional honey), so their muscle glycogen reserves would have always been lower than ours. They simply lacked the fuel injection of high glycemic load carbs to restore muscle glycogen concentrations following hard exercise. You now have this option. Not only can you
increase muscle glycogen concentrations via careful dietary manipulation but, by following our nutritional plan, you can also increase intramuscular triglycerides.

You, as a 21st-century endurance athlete, are no longer reliant upon the current scientific status quo relating diet to performance—you have the added advantage of knowing how the wisdom of your ancestral dietary background can improve performance. When you combine the best of their world with the best of ours, your performance will soar.

PART IV

P
UTTING
I
T INTO
P
RACTICE

CHAPTER 11