In news that shouldn't come as a shock to anyone who's carried a human being in her body for nine months, researchers have determined that pregnancy is really damn hard on your body.
In a new study, researchers at Duke University sought to find the limit of human endurance—basically, they wanted to know how much the human body can physically cope with.
Analyzing elite sporting events like the Tour de France and a 3,000 mile ultra-marathon, they found that the limit of energy expenditure was two and a half times the body's resting metabolic rate. For the average person, that means burning 4,000 calories a day. For reference, not even the world’s fastest ultra-marathoners managed to surpass that limit, the researchers found. Whoa.
If a person does surpass that rate, researchers found that the body starts to break down its own tissues to make up for the caloric deficit.
In addition to looking at the resting metabolic rates of extreme athletes, the study also examined pregnant women, finding out that yes, carrying a child is very physically taxing. As in, a woman's energy use spikes to 2.2 times their resting metabolic rate, only slightly lower than the maximum sustainable energy expenditure found among endurance athletes. Per a Duke analysis of the research, "This suggests that the same physiological limits that keep, say, Ironman triathletes from shattering speed records may also constrain other aspects of life too, such as how big babies can grow in the womb."
Did we need any more proof that women are superheroes? No, but it's still nice validation.