Grrrr, I had a writeup of tonight's Secret Science Club lecture by Dr Daniel E. Lieberman of Harvard University, and I somehow managed to delete the entire thing. The lecture, a companion to his book Exercised: Why Something We Never Evolved to Do Is Healthy and Rewarding, involved, you got it, exercise, which is a form of voluntary physical activity which is a recent behavior. Throughout human evolution and prehistory, physical activity was necessary for survival and for social status, so exercise per se was not a thing.
Right now, I'm really mad at myself for hitting the wrong key and sending my detailed post into oblivion. I will make sure to link to the lecture when a video becomes available. I think I'm going to take a shot of whisky now to dull my self-recrimination. Apologies to Dr Lieberman, Dorian and Margaret, and my readers. Suffice it to say, this lecture has been fantastic.
UPDATE: I figure I owe it to my readers, Margaret and Dorian, Dr Lieberman, and mostly myself to at least post a précis of last night's Zoom lecture. I was too miffed last night to post one, though, so here goes... I'm pretty much going to make it bullet point style.
Dr Lieberman's interest in human's running ability stemmed from his study of human heads, specifically the evolution of the nuchal ligament, which supports and stabilizes the head for running. This ligament evolved about 2.2 million years ago, suggesting that this is when human ancestors began their careers as runners.
Dr Lieberman was inspired to study exercise when he attended a conference while the Ironman Triathlon (a 2.4 mile open water swim followed by a 112 mile bicycle ride and then a full marathon) occurred. He was not so much interested in the reaction of the winner, who completed the event in eight hours, but in the reaction of participants who crossed the finish line close to the midnight cutoff time. He quipped that he himself has no desire to participate in this event, though he is a runner.
After this conference, he was conducting fieldwork among the Tarahumara of Mexico, who are famous for their long-distance running abilities. He observed two races traditional to the Tarahumara, a twenty-five mile race conducted by women carrying woven hoops, and a race run by teams of men who kick a wooden ball ahead of them as they run. Dr Lieberman requested that his interpreter ask race participants how they trained for the races, but the concept of training was foreign to the Tarahumara. One middle-aged racer, Ernesto, responded, "Why would anyone run if they didn't have to?"
Exercise is a particular form of physical activity, a wholly elective physical activity unrelated to work. It is a recent development, previous generations of humans typically got enough physical activity through the mere act of earning a living. Studies of the effects of exercise tend to be flawed because they focus on elite athletes.
The US government recommends a weekly minimum of one hundred and fifty minutes of exercise, though only 20% of Americans reach this goal. It is beneficial to change up one's exercise routine somewhat, such as inserting high intensity interval training into one's regular workouts.
There are myths about exercise, such as the myth of the 'athletic savage'- studies of hunter-gatherer communities suggest that they aren't typically stronger than people from industrialized societies, though they tend to retain more muscle strength later in life. The typical American or European sits for eight to twelve hours a day, while the typical hunter-gatherer sits for eight to ten hours a day. Activity costs energy, so people tend to save it for important actions. Humans tend to live beyond their child-bearing age, and grandparents are important providers for their families. Hunter-gatherer women of childbearing age tend to work two to four hours a day, while grandmothers tend to work four to eight hours a day, being free from child-nursing duties.
We evolved from couch potatoes- our closest relatives spend a lot more time lounging around than we do. It is rare for chimpanzees to walk more than two to four kilometers a day, and gorillas tend to find a spot with sufficient vegetation and remain there as long as possible.
Dr Lieberman described exercise as not being a 'magic bullet' that prevents disease. Exercising can lower the incidence of heart disease, diabetes, respiratory ailments, depression, and osteoporosis, but it is better to think that a lack of exercise increase the incidence of these conditions, a subtle distinction.
One of the themes that Dr Lieberman repeated throughout the lecture is that the important thing about exercise is to do whatever works for you, the importance is to exercise. Whether one exercises every day or several times a week isn't as important as exercising. He noted that it is not always easy to start an exercise routine, so incorporating exercise into one's social activities, such as finding a running partner, is helpful.
When the recording of the lecture is posted, I will post a link. In the meantime, kudos to Dr Lieberman, and Margaret and Dorian for providing a fantastic lecture. One of the themes that Dr Lieberman incorporated into the lecture, one that he uses as chapter headings in his book, was exercise myths that people believe. Here is the good doctor recounting five of these myths:
I feel better now, having picked up the ball that I fumbled so egregiously last night.