There has of late been a major shift in the pendulum of popular opinion about endurance athletics. Activities like distance running have fallen out of favor as evidence accumulates that it is not as healthy as once assumed. Training methodologies like Crossfit, P90X, Mark Sisson's Primal Blueprint, Robb Wolf's Paleo Solution all recommend high intensity, strength training, and sprinting as safer and more effective than endurance training.
I want to take a closer look at this trend as i believe that while strength and speed are invaluable, there are some significant paradoxes between historical evidence and the anti-aerobic point of view.
This topic has been beat to death in many circles but there is, in my opinion, still room for review, some useful discussion, and most of all some recommendations on avoiding the downsides of Endurance training if your going to do it.
Lets look at the reasons so many very intelligent people are criticizing endurance sports. Mark Sisson of the Primal Blueprint and Marks daily apple discusses his Case Against Cardio here, and why we are Not Born to Run here. He argues that we humans are excellent walkers, and decent sprinters but that running did not play a large roll in our evolution, and can cause injuries and health problems.
Art DeVany makes the case in his book the New Evolution Diet that the heart itself operates in a fractal pattern and that the constant heart rates of modern endurance training are actually teaching our hearts to beat abnormally.
Dr. Kurt Harris MD. at Paleonu.com has reviewed disturbing studies on marathoners showing abnormally high incidence of myocardial infarction, and heart damage in experienced runners.
The bottom line is that there is a growing body of research documenting higher than normal occurrence of injury, oxidative damage, and heart disease in endurance athletes.
There is also good research being done on the role walking and running upright have had in our evolution over the last 3-4 million years. Most every one agrees that it was bipedal walking that took us the first steps along the road from our chimp like ancestors to modern humans, we were walking upright long before serious tools and big brains arrived.
We have modern examples of Persistence Hunting in Kalahari bushmen, (who may be the oldest human population on earth) these hunts were actually witnessed and even filmed by scientists.
We know that bipedalism is measurably more efficient as a means of locomotion both walking and running, than quadrupedalisim. Harvard scientist Daniel E. Lieberman has proposed endurance running as a factor in hominid evolution and measured energy costs of walking and running for humans and horses.
There are also the stories like the one about Gordy Ainsliegh's horse pulling lame before the 1974 western states 100 race. Gordy competed anyway, horseless, beating most of the horses and inventing the modern ultra-marathon in the process.
So it seems the argument that distance running at least played a role in the development of our species is well supported.
So WHAT THE HELL? Why is the evidence so contradictory?There are, I believe, a few significant differences between competitive modern endurance sports and any running or persistence hunting practiced by our ancestors.
The first difference is Pace. Modern endurance sport is just that. Sport. It's competitive, athletes push themselves hard. Even a mediocre 4 hour marathoner is running 9 minute miles. While the bushmen in the persistence running study are running between 8 and 14 minute miles. One runner even reported that it was possible to hunt successfully if the hunters walked some of the time. The hunts are slower on average, involve several individuals who take turns chasing, and pace varies a ton throughout.
Next is the sheer Volume of training done by Endurance athletes. 10-20 hours a week is common, and 40 is not unusual in elites. Contrast that to the 20 or so hours a week of TOTAL work (work being defined as any physical activity necessary to gain food) done by hunter-gatherers. Your average hominid would do no work that was not strictly necessary and would have avoided uncomfortable activities like fast distance running whenever possible. It seems unlikely that any kind of persistence hunting would have been a daily occurrence. Once a week maybe but probably much less often.
Third we have all of the Lifestyle and Diet differences. The foods eaten by many, many amateur and professional endurance athletes are garbage. I think an argument could be made that a diet high in unhealthy carbohydrates like grains, and sugar as well as lots of processing and omega 6 fats can account for the health problems discussed above all by itself. The same can be argued for the poor sleep habits, and chronic stress in modern lifestyles.
My Conclusions.I believe the odds of our evolving one of the most efficient gaits on the planet, a laundry list of minor adaptations to walking, running and managing the heat produced, all happening by accident are remote. Persistence hunting is documented and possible. Humans are nothing if not resourceful, if we could do it I believe we did, if only infrequently. I think that the steady pace, relatively high intensities, and outrageous volume of traditional endurance, combined with poor fuels, and recovery are responsible for the health costs documented.
My experience, training myself and others, has led me to believe that endurance training is not mutually exclusive from strength, speed, or paleo. I think what most people believe is LSD is actually Long Moderate Distance, and that this misapplication is the root of the controversy. Following a few simple rules changes the game.
Doing it right.The "slow" in "long slow distance" means SLOW. Really slow, the pace cannot be stressful, or it will be counter productive to strength and speed. Think a stiff hike or casual bike ride, rather than running for time. The threshold between beneficial aerobic work and "chronic cardio" will be different in each individual, and depend on current fitness and training history. Paul Tergat, the world record marathoner, might run EASY 6 minute miles, I run easy 10-11 minute ones. You should feel more energized when your done than when you started. Its about metabolic and mechanical efficiency not horsepower.
Don't move consistently. Walk, then jog, then walk, then sprint, and so on. Hilly terrain makes this easier and more fun. What your after is an easy average with a big range of speeds.
Progress slowly. Have a plan, build in rest periods and don't ramp up volume to fast. Again, it should never feel difficult, pick a scenic trail and enjoy the views.
Spend most of your time working on skill sets. Running, cycling, swimming, hiking, climbing, whatever, take the time to learn how to move your body well.