As someone who write about health, people often ask me, “is lifting or cardio better?” While reporting my forthcoming book, The Comfort Crisis, I met a Harvard professor who gave me an interesting take on the question.
His name is Daniel Lieberman. He’s a Professor of anthropology at Harvard who studies the human body and how and why it came to be the way it is. He became famous for a 2004 Nature study called “Endurance running and the evolution of Homo.” Before that paper, scientists didn’t think running played a role in human evolution, because we’re terrible sprinters compared to most four-legged animals (e.g., try to race a dog).
But Lieberman argued that, sure, humans can’t go fast, but we can go far. We can run endless miles in the sun and not overheat. Other mammals burn up when they run on hot days. Humans are basically the best endurance species on earth.
He found that we developed adaptations like arched feet, long leg tendons, sweat glands, and more so we could run down prey in the heat. We’d chase the animal until it toppled over from exhaustion. Then we’d spear it.
Lieberman and I were talking about how comfort changes your body when he took me down a rabbit hole of exercise and strength. When we think about questions like “is lifting or cardio better,” he believes evolution can suggest answers for how we should behave today. And he told me that strength, which I wrote about extensively here, was probably not all that important as we evolved.
What Lieberman Told Me About Strength
“Strength is interesting because there’s a lot of ideas out there about how strong humans are and how important strength is. And it’s kind of a Rorschach test. There are a lot of people out there who love being in the gym and doing weights and dislike aerobic activity. They often pump up just how good resistance training is relative to aerobic training. And the reverse is also true—people who do aerobics and don’t like being in the gym are often dismissive of the importance of strength, right? Obviously they’re both important. But …
… But I think that the balance of evidence is that humans have undergone intense selection for endurance and aerobic activity and that strength is not as important in humans as it is in some other species.
It seems (our ancestors) had just enough strength for day-to-day tasks. Any weight-bearing task they did was probably based on bodyweight. There’s plenty of published data that suggests hunter gatherers are moderately strong but they’re not like today’s gym rats in any sense. They probably weren’t as extreme as many people in the gym today. Like, where would they find a bench press?
That doesn’t mean, however, that just because hunter gatherers evolved this way it’s better for you.”
How You Should Use This Info
- The Rorschach Test Lieberman alluded to is real: If you’re a runner, you should probably lift more. Vice versa if you’re a lifter. And same with your beliefs about each activity. Runners say strength training is overrated and will hurt you, lifters say running is overrated and will hurt you.
- Let’s say your fitness goal is general health and decent performance. If you buy into the idea that doing what we evolved to do has greater benefits than doing what we did not evolve to do, then two days of smart, challenging strength training is probably ideal. Devote other days of the week to endurance.
- Given how we evolved to walk and run long distances, covering five-ish miles a day (roughly 10,000 steps) on foot is probably pretty important for our health.
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