Babycham trainers with their Bambi style logo and bright colourful designers are perfect for the exercising princess! From the same brand who created the retro drinks the shoes and trainers are girly but adult, fun and (to cliché) functional. My personal favourites are the Fairytale Trainers below. The black canvas is decorated with a variety of colourful silhouettes featuring castles, frog princes and unicorns, as well as stars, hearts and butterflies.
The widest selection I have found is from Schuh but if your looking for the older designs lots of people are selling them on ebay.