A new study is proving what we’ve known all along: Pregnancy is an extreme sport. Or at least similar to one.
Researchers studied the metabolic rates of participants competing in endurance-testing events, such as the Tour de France and the Race Across the USA, and found that there is a limit to the amount of energy the human body can burn before depleting the body’s energy stores.
The study found that this limit is nearly the same in endurance athletes and as those of people who are pregnant and lactating.
The findings, published in the journal Science Advances, are that when the body is subjected to extreme duress — such as running a gazillion miles or carrying a small human around in inside you — the body finds ways to store energy.
“We were able to show that in the face of running a marathon a day, your body finds a way to save calories,” Herman Pontzer, an evolutionary anthropologist at Duke and co-author of the paper, told business journal Quartz.
According to their findings, athletes could not replenish their calories during long, high-intensity events.
In this way, these events were similar to full-term pregnancies: The body is pushed to its limits and can’t keep up with the calories being burned.
"You can do really intense amounts of work for a day or so," Pontzer told CNN. "But if you have to last a week or so, you have to maintain less intensity."
The study also analyzed data on the number of calories women burn while pregnant and lactating and found that they typically burn twice as many calories as normal.
Recognizing the massive toll that pregnancy takes on the body was a pivotal moment for researchers.
From Quartz:
"This realization was an exciting moment for Pontzer and his team. Among all apes, humans have one of the most energy-taxing pregnancies due to a combination of the length of gestation and the size of our babies. We’re also the best endurance athletes, as measured by our distance running capabilities. Our species’ metabolic cap could be the reason for both, he explained.
Pontzer theorized that evolution may have increased the physical endurance of humans, allowing us to have large babies. But conversely, evolving to be able to carry large babies may have allowed us to endure the rigors of extreme sports.
“There’s no reason it can’t be both,” Pontzer said.
