When a toddler takes his or her afternoon nap, the rest is well-deserved. That’s because the daily activities of a 1- to 3-year-old is equivalent to an adult completing a whooping 83 rounds of boxing. Now that’s a workout.

All the running around and playing a toddler does would also be equal to a grownup hiking to the top of a 10,000 foot mountain. (For comparison sake, Mr. Everest is 29,029 feet.)

Don’t believe us, just ask the dietitians at Growing Up Milk. They’re the ones who calculated the differences in energy exertion between adults and toddlers. According to them, parents need to be aware of how many calories their little tykes burn, and to feed them accordingly.

This would also go a long way to explaining why taking care of a toddler is so exhausting.