Many people are under the impression that you just can’t get enough exercise. A healthy activity must be healthier if you get more of it – right? Well, not necessarily; it’s possible to get too much exercise.
“Physical activity” is the term of art used in science for any movement of the body using skeletal muscles that leads to energy expenditure. Basically, almost anything other than sleeping or sitting in a chair involves physical activity, some of it strenuous – working a construction job, for instance – some of it much less strenuous – working an office job, or walking the dog.
Exercise isn’t synonymous with, but is a type of, physical activity. “Exercise is physical activity that is planned, structured, repetitive, and purposive in the sense that improvement or maintenance
of one or more components of physical fitness is an objective.”
Exercise is meant to improve physical fitness and health. To improve fitness, one must place a stress on the body, so that it responds to the stress by getting stronger and more resistant to injury, or by increasing cardiovascular capacity (VO2max) so that it can perform better the next time the stress is encountered.
Exercise is hormesis, or the process by which a low-dose stress or toxin improves health. But as with any stress, it can be overdone. Below is a chart for the incidence of atrial fibrillation in people who exercise (see previous link for details).
Those who exercised at high volume (not intensity as I explain in the previous article) had a higher incidence than those who exercised at moderate volume. It’s clearly possible to exercise too much.
Do non-human animals exercise? Some of them do seem to run around for no purpose other than the running, or perhaps enjoyment.
It’s possible that animals, including humans, have some kind of built-in need for exercise so that they can maintain their health. The cult of athletics goes back at least as far as ancient Greece, and in primitive societies, dancing and simulated fighting are common.
But, if there’s a built-in need for exercise, there’s also a built-in “exerstat” that tells an animal when to stop, when to rest. Animals rest when needed, and human hunter-gatherer societies are well-known for taking it easy when necessary.
We modern humans are capable of overriding our “exerstat”.
What happens when you override your exerstat? You feel rotten: tired, weak, and with a depressed mood.
Yet many people with these symptoms continue to exercise more than they should.
These people don’t understand that exercise is a stress, and requires proper rest and recovery.
In the video below, Doug McGuff, M.D. (“Body by Science“) discusses how his 3 times a week workout regimen made him feel like “crap”. He advocates a once-weekly workout now.
Exercise forces adaptive changes on the body. Like a drug, exercise requires a minimal effective dose. Just as giving more of a drug doesn’t always mean better results, more exercise doesn’t necessarily improve health either.
The multi-billion dollar fitness industry wants you exercising constantly, since there’s more money in it for them.
The health-conscious man often looks at the average person, who exercises little if at all, and says to himself, “I’m not going to be like that.” But he then goes overboard and exercises too much, doesn’t feel well, and wonders why.
It took me years of trial and error to discover my optimal frequency of exercise, which is currently two 35-minute sessions a week of high-intensity lifting. Sometimes even that feels like a lot. Before I cut back, I often had the same experience as McGuff: I felt terrible and had days where I didn’t feel like I was capable of doing much of anything.
If you do any sort of exercise of a higher intensity than, say, walking, your body needs rest and recovery. If the exercise isn’t too intense, you might only need a day. But if you lift weights, you need more time for rest and recovery.
Realize that exercise is a stress and it isn’t necessarily the case that more is better.
Besides improving health, the purpose of exercise is to make you feel better, with higher energy and a better mood. If exercise isn’t doing that, your dose may be too high, and you should cut back.
PS: For the best exercise, see my book, Muscle Up.