Bedtime - it's every parent's favorite time of day. But, when your tiny tot refuses to fall asleep, bedtime can become a nightmare for everyone.

Kids need their sleep, and parents need some downtime every day too. So, here's the solution: exercise -- no, not for you (though that's a good idea, too), but for your child.

A New Zealand study found that school-aged kids who are physically active during the day fall asleep faster than their sedentary peers. The study, which was published online in the Archives of Disease in Childhood followed 519 children with a mean age of 7.3 years.

They discovered that for every hour a child was sedentary, it increased their sleep latency -- or falling asleep time -- by 3.1 minutes.

Parents reading this are probably not surprised. How many times have you let your kids stay those extra 15 minutes at the pool or playground to wear them out?

In fact, New York University Sleep Disorders Center director Dr. David Rapoport, told Forbes sedentary children may just need less sleep:

I see this as something which we were designed by nature to do. The purpose of sleep is to recover from activity, and what this is showing is that that link is quite tight in the child. If the child exercises, they need more sleep and they get it more easily.

A 2008 study found however, that TV can disrupt a child's ability to fall asleep. Since today's sedentary kids spend much of their spare time playing video games, using the computer, or watching TV, they're especially at risk of not getting enough sleep -- even if they need less than active kids.

As an adult, I know I sleep far better when I'm exercising daily and so do my children.

Have you observed this effect in your own kids?