Every now and then I come across something that makes me re-evaluate my thinking in a fundamental way. Recently I came across an article by Mark Sisson, who according to slowtwitch.com is the architect of triathlon’s original anti-doping plan and both a prosecutor and defender of accused athletes. A former sub 2:20 marathoner and 4th place finisher in the Hawaiian Ironman, he now runs a popular health and fitness blog: marksdailyapple.com.
In this jaw-dropping piece and another longer article Mark makes a compelling argument against the popular belief that endurance/cardio training is a healthy thing. He claims it will decrease rather than increase your life expectancy. Mark is not one to beat around the bush and argues that endurance training speeds up the aging process “almost as fast as watching TV, drinking sodas and eating potato chips”.
Of course, this goes against the conventional wisdom that fitness is good for you and I must confess, it really got me re-thinking my own belief system. Mark argues the fact that human beings are not designed to work for extended periods of time at 80-90% VO2max.
“Our two primary energy systems are: (1) fat-based, which allows for long slow steady walking across the Savannah (or the Queen K after dark); and (2) ATP-based, which gave our ancestors 20 seconds of balls-out sprint speed to escape the charging saber tooth tiger (or let grandma lift the ’67 Ford truck off gramps when the jack failed).”
It’s a reasonable argument – he goes onto say our bodies are among the best in nature at adapting to hostile environments and self-destructive lifestyles. Essentially he class endurance sport as “hostile” to how our bodies are naturally designed to function.
Being a keen and enthusiastic endurance athlete most of my life, this was naturally a startling point of view! But for some reason what Mark was suggesting didn’t quite ring true. Maybe it was because I am now running more km’s per week and training as hard as I have in years… (my come-back phase sure) I am competing at high intensity levels, (albeit over shorter distances than an Hawaii Ironman), yet I have not felt this good in ages and certainly feel nothing but better for the experience! So here I’m thinking “am I missing something?”
After close examination I think I nailed the flaw in the argument. Mark went on to say:
The problem with many, if not most, age group endurance athletes is that the low-level training gets out of hand. They overtrain in their exuberance to excel at racing, and they over consume carbohydrates in an effort to stay fueled.
The key word here is “overtrain”.
In the comments of the second article a reader challenges Mark:
“It sounds to me like you experienced a classic case of overtraining and overuse injuries, and are now claiming high intensity cardio as the problem.
The problem was not the intensity at which you worked, but rather the frequency by not allowing your body proper rest and recovery. All exercise is beneficial (low intensity aerobic, high intensity aerobic, very high intensity intervals) to overall health. However, you must recognize the intensity and frequency at which you work and allow your body time to recover and grow stronger.”
To which Mark replies:
Not sure you got the message here. Of course I overtrained. That’s what many many marathoners and triathletes do.
Yes it is true that many marathoners and triathletes do overtrain, but this would suggest a more accurate premise for the article should be: over-(not cardio) training is detrimental to health/aging.
In Mark’s second article he speaks of the negative effects of his training:
The first signal I had that something was wrong was when I developed debilitating osteoarthritis in my ankles…at age 28. This was soon coupled with chronic hip tendonitis and nagging recurrent upper respiratory tract infections. In retrospect, it is clear now that my carbohydrate-fueled high-intensity aerobic lifestyle was promoting a dangerous level of continuous systemic inflammation, was severely suppressing other parts of my immune system and the increased oxidative damage was generally tearing apart my precious muscle and joint tissue.
It wasn’t so clear to me at the time exactly what was happening – in fact it was quite confusing, since I was doing so much of this so-called “healthy” aerobic exercise – but I had no choice but to give up racing, unable to train at anywhere near the intensity required to stay at an elite level.
For young and enthusiastic (and successful) athletes the mistake of over-training is a common one. To improve as an athlete, one must gradually and progressively stress your body harder in training. This process is called Progressive Overload. You do this by increasing both intensity and volume, over time.
Obviously the ideal way is one that maximizes results and minimizes injury. The key is a slow build-up and adequate rest between training sessions. If you increase the intensity or volume too rapidly or do not get adequately rest you are overtraining. Overtraining is a bad thing, that can increase your risk of illness, injury and the motivation to train. Mark’s account of his experiences clearly suggest he was in overtraining territory.
The logic of the last paragraph also strikes me as flawed: Mark claims he was “unable to train at anywhere near the intensity required to stay at an elite level”.
Firstly, while Mark was in overtraining territory he is right, his body would be physically weaker and his performances would have dropped accordingly. He simply would not have been able to train at a high intensity.
But part of the game in being an elite athlete is managing your training load. This means listening to your body and adjusting your training according to what your body is telling you. So if Mark were in overtraining territory as an elite athlete his responsibility at that point should have been to train less intensely not more!
By listening to his body and backing off he’d have recovered his strength, health and would have been back in shape in relatively short order (depending on how much damage he’d done to himself).
So while Mark certainly made some interesting and thought-provoking points, in my humble opinion he should be blaming overtraining for his drop in health, not cardio training.