The two groups that reach the peak of human endurance? Extreme athletes and pregnant women

(CNN)In pushing the boundaries of human endurance, extreme athletes and pregnant women are unmatched, a new study says. Longer pushes require lower intensities, but over a short period of time, the human body can successfully exert 4,000 calories on average before hitting the wall. That’s 2.5 times the basal metabolic rate, or amount of calories a body needs to operate while at rest. The average person won’t reach those limits in a typical workout (except maybe Crossfit, Pontzer noted), but pregnant women and extreme athletes cut it close. Weeklong races and nine-month pregnancies similarly push the body to its limits, often burning calories at a rate the body can’t keep up with. Original Article : HERE ; This post was …