Exercise w/ young kids

[Anonymous]

I'm looking for your creative ideas on how to get exercise when you're playing with your kids.

I have a 2.5 year old. When I get home from work all I want to do is play with my son, but I'd like to get some exercise when we're together that is fun for both of us. So far he's not interested in a dance party, watching me be goofy during an exercise video, and it's dark when I get home from work, so walk/running outside isn't really an option. What have you tried that works?

Elin