Luckily, a friend loaned me a prenatal yoga DVD so I could practice at home. Sadly, I'm 28 weeks along and finally found time this weekend to do a little yoga. The DVD is awful, but Ada (and Piggy) found a way to make it fun.
I think I got more of a workout laughing at her than I did doing the yoga. Either way, it was fun for the whole family.
Moral of the story: To make exercising more fun, find a way to include your toddler. You might not get the workout you expected, but you're likely to have a good time doing it.