Exercise - When you can't do it without them

 I recently began training for my first half marathon, but I'm finding it difficult to get my training in.  I don't have a good double jogging stroller, I'm way to tired and night, and mornings are complicated too.  I decided to just get up super early so I could exercise before anyone woke up.  I assumed that 5:30am would do it, but no.  As soon as I started getting up at 5:30 they started getting up at 6-6:15, not enough time for me to make my husband's lunch and run 5-10 miles.  Why can't things go according to plan?
I'm constantly coming up with new strategies.  If they wake up and come downstairs I have them sit next to the treadmill and watch a cartoon or read a book in bed.  I invite them to do video workouts with me.  I even let them have turns on the treadmill, but when it just doesn't work out I've started biking.  My two oldest are in school so I buckle the younger two in the bike trailer and off we go.  They've done really well for the first several miles.  I normally go when my baby is starting to get drowsy, and as long as I don't stop or hit too many potholes he lays back and zones out or falls asleep.  The 4-year-old gets bored after a couple of miles, and starts whining which of course brings the baby out of his happy place and he starts to cry.
I realized while riding one day that there is a park about halfway through one of my popular routes, so today I offered to let her go to the park for 15 minutes in the middle of the ride.  Of course she couldn't wait to go, and the only slightly whiny type sound that I heard from her was an, "Are we there yet," when we were about a block away.  We got to try out a new park and go down the giant, yellow twisty slide, and she was convinced that the baby would love the little, tiny, pink slide.  After that exertion the ride home was quiet and peaceful, other than the traffic, and I consider it a complete success.  What I learned?  My kids are not motivated by the, "Mom is trying to maintain her girlish figure," goal that drives me.  I have to help them find something in it for them.