Your days are full of work, taking care of the home, the kids, and yourself.  It's hard enough to fit all those things in and find time for fitness.  When you cheat yourself out of your fitness time, you're not just cheating yourself.  You're cheating your family too.  They need you at your peak.  If you take care of yourself, you set the example for your children.  They will emulate your good habits just as easily as they'll emulate your bad ones.  Why not let those little bundles of energy help you meet your daily fitness goals?

• They never seem to get tired.  So you've been kicking around a ball with your kids in the backyard for the past 20 minutes.  If it was up to you, you'd stop now.  This is rather boring, and it stopped being fun five minutes ago.  But the kids want to keep playing.  All right, you say, ten more minutes.  Tada!  30 minute workout done with quality time with the kids thrown in.
• They have an amazing sense of wonder.  Have you ever been to the zoo with a child?  Everything is new, exotic, and exciting.  All the exhibits become a distraction to the long trek around the winding trails to see them.  Your feet are always less sore when you're having fun.
• They will find any opportunity to dance.  If you have an especially young kid, like under the age of four, they love to dance.  Almost every kid loves music, singing, and moving to their own beat.  If you're not a fan of kids' shows that encourage kids to get up and move (and Mom along with them) there are lots of other ways to find a beat.  Online services like Pandora have playlists for kids and parents already put together, and the best part is it's free.

Kids are a great motivator to do something good for yourself.  Whether it's signing up for a program like Michigan's Adventure boot camp or just playing with them, kids are an excellent tool to keep yourself fit.  Who says you have to spend money on an expensive gym?  You have your own little personal trainer sleeping in the next room.