Stretching before and after a workout helps loosen muscles so rather than building bulk you're builidng lean legs and arms. Combine the benefits of stretching with balancing on one foot and you've got a nearly perfect exercise.
Check out this fitness video to learn how to do a yoga pose where you balance on one foot while holding the toe of the other. This is great for building core strength as well as flexibility.
Have an iPhone? Check out all 200+ new features coming in iOS 13.