Excercising with the Family

My husband has been doing Insanity with the kids. I am amazed at what they are capable of doing. They actually look forward to it. I love that my husband takes time to work out with them. He also takes them on a walk almost nightly. And by walk I mean they walk about 3 miles or more. I am excited to get back to walking with my family after the baby comes. How do you get your kids to exercise? For our teen he has to earn video game time by exercising. He currently uses the elliptical. Pamela