I've been considering something like 10 minute solution pilates because you won't have to worry about kicking your kids while you're doing it. I have no flexibility in my spine though (spine fusion) so I'm not sure whether I could actually do it.
Does your wagon have a seatbelt? I've been considering getting one of these. My 16 m/o is almost 20 lbs. and it's killing my back. The thing is,...how fast can you walk pulling a wagon? lol
Let me know if you think of something. I need ideas.
Edit: I just found
this. It looks interesting...I think I will check it out tomorrow when I go to the shopping.