Incorporate kids into your training.
For example, the week before the Pilgrim Challenge I found a way to take my daughter (age 5) along for my runs. Disclaimer: DO NOT TRY THIS AT HOME!! I tied a scarf around my wrist and the other end to her scooter and basically dragged her through the streets of London. She had a blast, she was flying. Sure, she fell a few times but no harm done. The best part? Our chocolate cake break!
My son (age 9) is old enough to accompany me on his bike. We've done up to 21 miles this way, me running and him cycling behind. As long as I keep him carb-ed up, he doesn't want to stop.
Don't forget the baby! i just finished 100 squats with the baby strapped to me in the baby carrier. He laughed the whole way through, thinking it was some sort of game, while I did my parental duty and took care of the little one for a bit. Not to mention the extra 12 lbs helped my workout.
We also choose events that are in locations we want to holiday in. That way it's a win win. We plan the year in advance, choosing the destinations that appeal to us and dates that fit our calendar.