It’s a bird! It's a plane! No, it’s someone who is seven months pregnant, walking down the road like a spacehopper rolling through custard and operating at an a level Superman can only dream of. No, really – a new study has shown that during pregnancy we exist at nearly the limit of what a human body can endure – and judging by the many WhatsApp messages from pregnant friends I’ve received today saying something along the lines of “SEE! I TOLD YOU SO!”, it’s something they’re already highly aware of.
The study, published in Science Advances, looked at how much energy a human body could use for a prolonged period of time without having to start breaking itself down to make up the energy deficit. Researchers at Duke University in Northern California analysed extreme sporting events like the Tour de France and Race Across the USA (where athletes run over 3,000 miles in 140 days) and found that after an initial burst of energy, the limit of what a human body could push itself to for a long period of time was 2.5 times their normal metabolic rate – or, for the average person, the equivalent of burning about 4,000 calories a day.
And pregnant people? They use about 2.2 times their resting metabolic rate. For nine months. Next time your pregnant friend tells you that she’s too knackered to go to the pub with you, she’s really, really not lying.
Professor Herman Pontzer, an evolutionary anthropologist and co-author of the study, explained that pregnancy doesn’t quite hit the same metabolic rate as that of the athletes because pregnancy lasts longer and it requires weight gain rather than just weight maintenance. Still, even if pregnancy’s metabolic rate is a whole 0.3 less than that of the long-distance athletes, the Race Across the USA lasts but 140 days and pregnancy lasts 280. It’s clear which one is more impressive, no?
We already know that human pregnancies are the most physically demanding of all ape pregnancies because of both how long they last (I’m six, long months in) and the size of the babies (my baby’s head is currently in the 90th percentile (RIP my vagina)). We are also the best endurance athletes out of all apes, able to run distances they couldn’t dream of – and this study shows that it’s possible these two facts are linked.
As Professor Pontzer explained, “The fact that pregnancy seems to be in the same mix as the other activities is a clue that the machinery has all evolved to enable the really expensive pregnancies that humans have, and it's had knock-on effects to this machinery that allows us to do these big endurance events.” Or, in other words, the reason your weird mate Dave from school can do all those Ironmans is because we evolved to be able to cope with these long, exhausting pregnancies – or, conversely, that we have these big, clever, highly evolved babies precisely because we are physically capable of growing them. Either way – Dave, you’re welcome. Payment in Dairy Milk and back-rubs, please.
Since the study came out, pregnant women across the internet have been sharing their relief at finally having some justification for how they’re feeling in their pregnancies – namely, exhausted and permanently hungry. And the good (?!) news is that lactation uses as much energy as pregnancy, so if you have a baby and then breastfeed it for six months, you’ll be doing it for around 420 days. Superman, eat your heart out.
If nothing else, the news of this study has made me feel much better about the time a few months ago, when I was four months pregnant, I put spaghetti Bolognese on top of a pizza and ate the whole thing to myself. In front of the TV. With my feet up. Alongside a portion of chips. Now I know that I was essentially just carb-loading, right? If it’s good enough for the endurance athletes, it’s good enough for little old pregnant me. Pass the potatoes, please. I've got some energy reserves to fill.