What’s the point of exercise?

Exercise is a relatively recent phenomenon. After all, it’s difficult to imagine a caveman on a treadmill. And it’s safe to say that paleolithic humans never pumped iron. But something changed as we moved from the plow to the Peloton. Exercise — physical exertion for the purpose of improving health or fitness — became a huge part of modern life, and a nearly $100 billion global industry. 

But why do we spend so much time and money at the gym or on the track, and does it actually help our well-being? And why is exercise, at least for some of us, such a miserable experience?

Daniel Lieberman, professor of human evolutionary biology at Harvard University and author of the book “Exercised: Why Something We Never Evolved to Do Is Healthy and Rewarding,” has some fascinating answers.

Three Takeaways:

• We often think of our distant ancestors as great athletes. While they might have been in better shape than we are, they certainly didn’t look like The Mountain from Game of Thrones. Lieberman points out that our ancestors didn’t engage in physical activity because they wanted to be strong or fit; they did it because they had to. And even then, they weren’t “working out” as much as you might think. Lieberman cites the Hadza, a hunter-gatherer tribe in Tanzania. They only engage in about 2 hours and 15 minutes of “moderate-to-vigorous” physical activity per day. After all, if you don’t have access to an infinite number of calories at your local grocery store, it doesn’t make sense to spend excess energy on physical exertion.
• It’s easy to be confused about exercise and physical activity, because there is a fair amount of conflicting information around. (Running barefoot is good for you! No, it’s bad for you!) And it can be difficult to tell what’s correct. For example, if you’ve heard that “sitting is the new smoking,” well, according to Lieberman, that’s not quite accurate. It’s not necessarily sitting that’s the problem; instead, it’s a complete (and sustained) lack of movement. If you go from sitting at work to some physical activity afterwards, that could be fine, but if you go from sitting at work to sitting at home, that might be an issue. And even if you have to sit for hours and hours, Lieberman suggests getting up from time to time to stretch your legs. 
• Lieberman says more nuanced messages about exercise are important, and it’s wrong to think that exercising a lot will ensure weight loss. After all, physical activity probably doesn’t burn as many calories as you think. (It depends on the donut, but if you walk for an hour, you’re probably not going to burn that donut off). But that doesn’t mean physical activity isn’t important. Though exercise may not make you lose weight fast, Lieberman says it’s good for your health in general, particularly in preventing weight gain. Plus, it has a lot of surprising health benefits, including possibly helping to prevent Alzheimer’s. And if you absolutely hate exercise, you can start small. Studies show that even short amounts of exercise can do a lot of good.