DISCLAIMER: I am not a doctor, personal trainer, or healthcare professional. These are just my opinions. Consult a physician before starting any exercise program.
If we could give every individual the right amount of nourishment and exercise, not too little and not too much, we would have found the safest way to health.
HIPPOCRATES
Zone 2 is defined as training at 60-70% of your maximum heart rate. A slow jog or a brisk walk achieves the requirement for Zone 2 training. Experts recommend doing 180 minutes or 3 hours per week of Zone 2 training comprising 60-80% of training volume. Zone 2 training has become the rage among the exercise community, and I can understand why. I believe the human body was designed and optimized for Zone 2 training because it is what you do when you walk or work in the garden. I don't think the human body does well when it goes beyond Zone 2 for long, and it certainly doesn't do well below Zone 2. How do I know this? I've done both. Neither a sedentary nor an intensely aerobic lifestyle were good for me. I hit the sweet spot with a daily walk of an hour at the Zone 2 level.
I think brisk walking and doing manual labor in the yard and garden are the best forms of Zone 2 training. It is virtually impossible to overdo it. This is in contrast to Matt D'Avella's 30 day experiment with Zone 2 training:
I tried zone 2 training for 30 days (what I learned)
One of the things I find annoying about Matt D'Avella is how he can do something for 30 days and learn absolutely nothing. He did this with 10,000 steps and using a dumbphone. After 30 days, he goes back to where he was before like a dog returning to its vomit. These videos represent stunts for clicks. But what I found interesting was Matt's struggle to stay under the threshold for Zone 2 training as he jogged and rode a stationary bicycle. I think if you have to wear a heart rate monitor to remain in Zone 2 then you are doing it wrong. This is why I think walking is the better way to go. Unless you are doing that contorted race walking thing, I don't think you can walk yourself out of Zone 2.
I have really taken to the idea of exercise as medicine. As with any medicine, it comes down to taking the proper dosage. Too little is ineffective while too much is deleterious. This flies in the face of the conventional wisdom that you can never exercise too much. As I pointed out in these two previous blog posts, you can overdo exercise:
The Tragedy of Micah True
How We Got The Extreme Path Of Fitness
I don't know the precise point when exercise becomes too much, but that point exists. People in the marathoner/ultramarathoner category certainly qualify with the evidence of cardiovascular damage and increased risk of colon cancer. I remember reading that the conventional wisdom among doctors in the seventies was that you can overdo running, hurt yourself, and damage your health. The runners of the running boom set out to prove those doctors wrong. After all these decades, I think the running boomers have proven those original doctors right. This is an interesting study:
Dose of Jogging and Long-Term Mortality: The Copenhagen City Heart Study
And here is the interesting bit:
The findings suggest a U-shaped association between all-cause mortality and dose of jogging as calibrated by pace, quantity, and frequency of jogging. Light and moderate joggers have lower mortality than sedentary nonjoggers, whereas strenuous joggers have a mortality rate not statistically different from that of the sedentary group.
It seems that leaving that sweet spot of moderate jogging and going into the strenuous zone decreases lifespan. Basically, an ultramarathoner or a marathoner at an elite level lives no longer than a couch surfer.
Why run? Clearly, you can get the same benefits from walking though it may take more time. The supreme benefit of walking is that it is more pleasant and more gentle on the body. This makes it a more sustainable activity as people tend to stick with things they enjoy instead of hate. This brings us to the knee question.
The conventional wisdom is that running is bad for the knees. Research indicates this is not the case. I think this research is prone to survivorship bias as runners with bad knees tend to give up running and remove themselves from the pool of surviving runners. This leaves the outliers who run without significant damage. What if there was a runner stupid enough to severely damage his knees and keep on running? That runner exists. That runner is David Goggins:
Joe Rogan on Goggins’ Knee Injuries
David Goggins talks about his knee problem
There are some crazy folks out there who admire David Goggins's dedication to running. I just appreciate that the guy has made a human guinea pig out of himself to make my anecdotal point that running is bad for your knees. Then, there is Scott Douglas on the topic:
Nobody Knows How Many Runners Get Injured
And nobody knows what “extreme exercise” means.
Scott got injured from running. It was a nasty injury requiring surgery. Here is a telling quotation:
Having one seems kind of important for what might literally be a matter of life and death. Yet if you look through the research on the topic, what counts as extreme exercise is all over the place. Sometimes it’s years of running, sometimes it’s volume or duration, sometimes it’s intensity, sometimes it’s some combination of volume and intensity and duration, sometimes it’s number of marathons and/or ultramarathons and/or triathlons, and so on.
This vagueness just won’t do, given the presumed goal of providing public health guidance. How are we to know if we’re even in the pool of at-risk individuals, much less whether this is something to act upon?
The whole article is worth reading because you see a man forced to consider the possibility that he is overdoing it because he has seriously hurt himself and has some troubling issues with his heart. Faced with the prospect of giving up running, Douglas falls back to the "vagueness" argument you might hear from an alcoholic in denial. How many drinks is too much? Since no one seems able to draw a hard and sharp line on the matter, the extreme is still the way to go. Personally, I would see that line of stitches on my ankle as the hard and sharp line telling me to rethink things.
The problem as I see it is that sedentary people eschew exercise because they believe falsely that they have to train for and run marathons for it to count. Conversely, dedicated runners are too afraid to cut back or give up running in favor of walking as if they are going to miss out on additional benefits like they are forfeiting lottery winnings. These extremes of sedentary and excess overlook the benefits of a moderate program of exercise as recommended by the research and health professionals going back to Hippocrates.
Moderation is not a popular prescription especially in the United States. Americans are peculiarly given to extremism. I think this comes from equating extremism with greatness. Here is Navy SEAL Jocko Willink on the topic:
Accept That Some People are Okay With Being Mediocre
Being "mediocre" is a bad thing. The issue here is that moderation is equated with being mediocre. Jocko says that he sleeps 5.5 hours a night where 8 hours is the moderate amount. Sleep deprivation equals success. Success requires "extreme ownership." Naturally, this sells well to Corporate America (Jocko's clients,
Echelon Front) trying to motivate their salaried employees to "greatness." It is strange how this greatness corresponds perfectly with their greed. But I digress. . .
I doubt that Jocko reads Aquinas, Aristotle, or Hippocrates and their call to neither deficiency nor excess. I have personally been on various paths of extremes, and they never end in a good place. I suppose I am now on a path of extreme moderation in all things. Moderation is not mediocrity. It is common sense. Common sense is an endangered species in today's world of extremes, but I know that common sense never dies. It always makes a comeback when people realize their errors. With exercise, a moderate dose is what the doctor ordered.
UPDATE: I came across this great quotation:
Walking five miles a day or more provides the type of low-intensity exercise that yields all the cardiovascular benefits you might expect, but it also has a positive effect on muscles and bones - without the joint-pounding damage caused by running marathons or triathlons.
DAN BUETTNER
I also came across this great YouTube video that gives updated information on the things I've been sharing here at the C-Blog in regard to endurance exercise:
More Exercise = More Plaque
One of the issues with these studies is the lack of information on diet and nutrition. The tragic death of Jim Fixx showed that you can't outrun a bad diet. But from what I have gathered, you can overdo exercise, and extreme exercise does not improve health but damages it. Once again, it comes down to the dosage. Moderate exercise is the way to go.
