I stumbled across a blog post titled Conflicting Cardio that pondered aloud the following:
As I read Mark’s essay, I distinctly remembered hearing advice somewhere that completely contradicted what he was saying. I remembered reading that we were actually genetically designed to run long, slow distances, and that the way our ancestors hunted was not in short sprints (antelope would outrun us no problem), but rather in long, slow jogs, waiting for the animal’s body temperature to overheat. At that point, the animal simply passed out from heat exhaustion, and we moved in for the kill. This is based on the premise that human beings evolved an evaporative cooling system, whereas animals didn’t; they don’t sweat, and thus, they’re terribly inefficient at cooling their bodies during exercise.
Fortunately for you, I have a spectacular memory. The article I’m referencing was from an issue of Men’s Health that ran about a year ago, titled Yes, You Were Born to Run. The author, Richard Conniff, based the article on research conducted by Daniel Lieberman PhD, a University of Utah biologist.
I find this situation particularly hilarious because it illustrates perfectly the dilemma that the typical North American finds itself in when attempting to establish what, exactly, is good for us in terms of our health. Is it low-fat or low-carb? Steady-state cardio exercise, or HIIT (High Intensity Interval Training)? 12-15 reps or 6-8? The amount of conflicting information published is astounding.
What is the right combination of cardiovascular exercise and strength-training? Is one better than the other? Is endurance exercise healthy? These are important questions to ask.
Here is my brief take, which is cross-posted as a comment on Becoming Adonis:
Seems to me that any “cardio” should be conducted at low-intensity. “Intensity” is incredibly vague, so for my purposes, I am defining it as whatever rate at which my body burns mostly fat for energy. For most of us, I imagine fairly low levels of exercise — probably less than jogging but greater than walking (Though walking with weight could serve in a pinch). For individuals who train for endurance, the level will be higher as their bodies are more efficient at burning fat for energy — I’m thinking specifically of Ironman athletes or other high endurance individuals who necessarily blow through all of the glycogen stores in their bodies and simply must burn fat for fuel. For a discussion on this, see Mark Twight’s write-up on endurance and fat (here).
Based on a number of articles about endurance exercise (See More Reading below), I don’t see a lot of benefits in endurance training. I’ll save further discussion on that topic for another time.
Meanwhile, HIIT and/or weight lifting is right up the alley of most all of us mere mortals for the very reasons Mark Sisson and you describe (Sprints being a great example).
How do we put all of this together? Do we just ditch cardio/endurance exercise altogether?
Modern man is scarcely active relative to our ancient ancestors. Hunting/gathering at the grocery store is hardly going to require a lot of energy nor is typing 90wpm or clicking a mouse. The big incongruity is simply a lack of basic, low-intensity activity that would have been a matter of course to paleo man but is a foreign concept to us bloggers.
So what is the solution? We should simply seek to be more active at low-levels of intensity. This means more walking (perhaps weighted) or perhaps low-intensity biking or mountain biking. I imagine there are a number of competitive sports that could also fit the bill here. Mix these activities with HIIT and weight-lifting and you’ve got an optimal combination.
- Did you happen to see this post by De Vany on sweating? Totally jives with the evaporative cooling mechanism discussion in your post.
- The Men’s Health article referenced can be found here
And a bevvy of articles on endurance exercise, most which question its health benefits:
- Recent Triathlon Deaths Have Experts Searching for Answers (NY Times)
- Death by Exercise (Men’s Health)
- The Legacy of Jim Fixx (halhigdon.com)
- Running Yourself to Death (The Voice of Prophecy)
- They’ve made it! Seven marathons in seven continents in seven days to help fight heart disease (British Heart Foundation)
- Art De Vany: Top Ten Reasons not to Run Marathons — Coronary Heart Disease in (you guessed it) Marathon Runners — Marathoners and Other Sick People