One of the more "interesting" things I find with most hardcore advocates of the Paleo or Primal diets is that they love to use the evolutionary template when it suits them and discard parts of it that don't jibe with their preconceived notions of what they believe to be optimal. I have been guilty of this at times myself. A couple of great examples are the use of starches in the diet and the predominantly meat-heavy diet they believe our ancestors ate. There are a couple of great examples of hunter gatherer tribes that eat tons of starches with no ill effects, the Hadza being the most well known. As far as meat being a huge part of the diet, this is debateable. What is not debateable is that large fatty cuts of meat were not the norm. Just because a hunter gatherer didn't discard the fat from a lean animal doesn't mean they ate fat ad libitum in the same vein as bulletproof coffee. What is also not debateable is that even if they ate a more animal-based diet, they were doing so while also consuming 100-150g of plant-based fiber, something you are unlikely to get with today's vegetables without high doses of supplemental fiber. This would be highly protective of the microbiome that our ancestors had and makes your bacon and nut butter-based diet not applicable to theirs.
Another great example of ignoring the data comes in the form of eschewing exercise in the aerobic energy pathway. There are numerous traits that humans have evolved that set us apart from our primate ancestors and make us incredibly adept at endurance running. You can see this anatomically in the way that we are built as well as physiologically in the way our energy systems operate. These adaptations include adaptations to the tendons and ligaments that allow for greater forces, enhanced thermoregulation through sweating, glutes that can generate large forces and help stabilize the leg, a pelvis and spine that can absorb and stabilize against greater forces, larger joints surfaces in the lower body to improve shock absorption, and a foot well adapted to generating large forces(1).
A body that can absorb large forces like this, from a walking perspective, is unnecessary. It's also unlikely that animals that were once our prey were being sprinted down by a much slower animal. Since some of these adaptations predate modern humans, and weapons used at the time were not sharp enough to pierce the flesh of animals when thrown from a distance, it seems likely that endurance running may have been something that drove the evolution of modern humans. (For a more thorough rundown of this, I recommend the book The Story of the Human Body by Dr. Dan Lieberman). In addition, many of the adaptations to endurance exercise that we see in modern research imply that endurance running is indeed important to human health.
There are other benefits of endurance exercise that show great promise in human health, and many of these are separate and sometimes diametrically opposed to resistance/sprint training. Quite a few of these adaptations are complementary to the adaptations of resistance exercise and affect the brain as well as the cardiovascular and immune systems. Over the course of the next 2 blogs, I will take a look at the adaptations to both strength training and endurance exercise and how you can practically apply this information to enhance your health.
In the first blog, we will go over what the research shows us to be the beneficial adaptations from strength training and endurance exercise. Do you eat MCTs or coconut oil for the ketones? Are you looking to improve your ability to burn fat efficiently? Is brain performance important to you? Will a robust immune system improve your quality of life? We'll take a look at how resistance and endurance training each affect these systems and why ignoring endurance exercise is a mistake.
In the second blog we will go over how we can apply this information to your exercise program. How much? How often? How intense? What kind? All of these questions are important and we will cover them all.
Hopefully this series gives you a new appreciation for an exercise modality you have likely been ignoring while following a Paleo or Primal lifestyle. While strength training and sprinting are both excellent forms of exercise, they do not provide you with all of the benefits you could be getting from a program that includes both of these modalities with endurance training.