If you want to be a one of those cute couples who exercise together, then be prepared for her to turn down your suggestions of going for a nice run together, unless you've provided her with three sports bras. This isn't a choice of out three sports bras which she likes the most, she'll probably have to wear them all. You can't sneak a run up on her so if you want to do something physical that doesn't involve the two of you in the bedroom, then maybe think of another activity.