A new study conducted by Duke University researchers has revealed that there is a limit for human endurance. The research report revealed that the endurance cap is 2.5 times the body's metabolic rate or in simpler words, it will be 4,000 calories a day for an average person. As per the research, anything higher than this cap will not be sustainable for an average individual in the long run.
The study report published in the journal Science Advances also revealed that pregnant women are endurance specialists, as they can live at an endurance limit the human body can maximumly cope with.
During the study, the team of researchers looked at the athletes who competed in a 140-day 3,080 mile run across the United States, and they later analyzed the effect of the long run on their body. Later, researchers measured the resting metabolic rate (RMR) when the body is not active, both before and after the race. It should be noted that the resting metabolic rate is basically the calories that the body burn during the time of resting.
Researchers also noted that the length of the sporting event and the energy expenditure has direct relation. To make things clear, marathon runners used 15.6 times their resting metabolic rate, but these events last only for a day. On the other hand, during the 23 days of the Tour de France used 4.9 times their RMR.
"You can do really intense stuff for a couple of days, but if you want to last longer then you have to dial it back. Every data point, for every event, is all mapped onto this beautifully crisp barrier of human endurance. Nobody we know of has ever pushed through it," Dr Herman Pontzer, from Duke University, told BBC.
The researcher also added that this new finding will help athletes to perform well during extreme sporting events.
"In the Tour de France, knowing where your ceiling allows you to pace yourself smartly. Secondly, we're talking about endurance over days and weeks and months, so it is most applicable to training regimens and thinking whether they fit with the long-term metabolic limits of the body," added Pontzer.