Early Lessons

K and I were getting ready to go for our walk the other day, when she asked if we could jog. That would be a great idea, if only my chest was about 5 cup sizes smaller! How do you appropriately explain to your six year old about such matters? Hopefully she is not nick-named "Perky" or "Jugs" by stupid boys like her mother was (preferably this gene was not passed to her).