According to a new study, kids are naturally just about as fit as PROFESSIONAL ATHLETES.
The researchers studied boys between eight and 12 years old, and found that their muscles basically don't ever get tired like yours do.
Can't keep up with your kids when they're running around and playing? That's okay. You couldn't keep up with LeBron James either.
The kids also recovered, quote, "even faster than well-trained adult endurance athletes."