It is amazing how much energy children have. I have heard a theory that they have the same amount as adults, though with adults it is spread wider since we are bigger. Today, I attempted to tire out my toddler. We went on a shopping outing since we were all due for some new athletic shoes. After that was lunch. After lunch we went to the park to play on the swings (parks with swings are wonderful, by the way). She also played on the slides and the little horses on a spring. Then she walked all the way back to the house (about half a mile). Back at the house there was a pile of leaves waiting to be played in. She and her sister were having a blast. By the time we came back inside it was 2:30 pm (about half an hour after her late naptime). Mommy got a phone call and she was running around playing. It was about 3:00 before she got down for a nap. She went willingly (though she usually does). Would you believe that she only slept an hour and a half? At this age, her older sister took three hour naps on a regular basis.
The older child doesn't take naps anymore (though she sometimes konks out on an especially tiring day if I put in the car to go somewhere). Both kids are fairly energetic. My oldest currently wants to be a ballerina and will dance for hours, music or no music. She has always been pretty active too. Although, they get video time which is often seen as couch potato fodder and leading more kids to obesity. My kids manage to eat well (though pickily) and burn off the energy so well that they are average weight or less for their age while being very tall (95th percentile at least).
Mommy remembers her childhood and I was much the same as a preschooler. I was always tall and thin too. But, from mid-elementary school on, I tended to be a tired kid (I had anemia issues). However, although I like to be fairly active and go for walks, I do not have nearly the energy I need to be active at the same level as my kids. There are times that I wonder if I am absolutely insane to be having more kids. Then I shake myself out of it and tell myself that I may not have their energy but I can use my cunning. That will have to carry me through until they hit the tired years like us old folks