*Note from Sarah: Jason Seib is back with a MUST READ article!!
Whenever I tell people to stop doing cardio I always seem to leave them baffled. The concept of cardio for weight loss is so ingrained in the minds of most people in the Western world that it tends to go without saying that it must be done. Sometimes people even leave it out when I ask them to tell me about their workout routine because they assume cardio is a given. In truth, Sarah and I (and Robb Wolf, Mark Sisson, and Chrissy Gower, to name a few more of MANY) prescribe no cardio to our clients at all. Yes, that means Deb did absolutely no cardio to get her results. I know it sounds crazy, but ask yourself why you believe cardio is beneficial as we take a look at the logic and science behind why it is not. First the logic, then the science.
Just to be clear, we define cardio as sustained effort at intensities above walking and below sprinting. Walking and sprinting = good. Running marathons = bad.
The logic behind avoiding cardio taps into one of my pet peeves, so I’m sorry if I come off a little harsh. We are so programmed by the “______ Diet” mentality that it never crosses most people’s minds that the evolutionary perspective used in the paleo diet should be applied to all things that affect our health. We choose to eat this way because we are pursuing natures intentions for human nutrition, only to strap on our Nikes and head out the door for a 5 mile run without ever considering whether or not this is something we should be doing. The question becomes, where is the stimulus in nature to engage in this activity? In other words, what would have caused us to run any more than a mile or two in nature often enough for natural selection to make us great at it and spare us from ill effects? It wouldn’t take a tiger than long to catch the fastest of us. It’s funny that in the minds of most Americans you aren’t truly fit until you have attained the useless ability to run 26.2 miles. An incredible feat, but not one that will ever come in handy.
No doubt I am making a few people angry here, but endurance sports are sports, not methods of attaining better overall health and fitness. If you enjoy running marathons, then who am I to tell you to quit? Just understand that running marathons is not good for you. Neither is playing at a competitive level in most other sports, but that isn’t why we play them. We play sports because they are fun. Oddly, the vast majority of runners are not competitive and run because they believe that what they are doing is beneficial to their health, and all other forms of cardio and cardio machines that I am aware of attempt to simulate the same internal processes that we get when we run. The unfortunate thing is that they do simulate those internal processes.
Now for the basic science. When it actually works, the “fat burning” effect that is the goal of the cardio-for-weight-loss advocate is mostly due to stress, and even then the results are sub-par compared to exercising in a manner that the human body understands. When you head out for a run or jump on an elliptical machine for an hour, your body produces the same hormones that make humans great at sprinting. Cortisol in particular is produced to get you some quick blood sugar for a fast escape or to catch some dinner. But you never make that quick escape or catch that dinner, and you are never caught and eaten by something scary, you just keep running. And your body just keeps producing cortisol. Internally, this is just stress, but we call it exercise and do it 3 – 5 days per week, even though that last little bit of belly pudge won’t go away. That little bit of pudge is so stubborn because your body is in a panic and it is trying to keep some energy stored close to your organs where it will need it most through this time of hardship.
For the actual studies and data, I can’t compete with Dr. Kurt Harris’ posts here and here. They are phenomenal and well worth reading in their entirety. They also contain the hard science that, for me, completely negates any citation of persistence hunting tribes as reason why we are “born to run”.
If you are doing cardio on a regular basis, ask yourself why? If you are an endurance athlete, then you have a valid reason. Since most of us are trying to be lean and healthy, then don’t you owe it to yourself to try a more evolutionarily sound training protocol for a few months before you assume that you need cardio? It’s hard to argue for the necessity of something you have never tried going without. So what should you do? Sprint like hell for short distances, walk as far as you want, lift heavy things in as many ways as possible, and mix it all up using high intensity intervals. If you need further guidance, Sarah happens to have an excellent fitness section in her book.