I've been walking to work and back every day, which is a total of at least two miles. I work on the third floor at work and live on the fourth floor of my apartment. I use the stairs - there are no elevators. I've been doing this for six weeks every single day and my legs are really flabby (my calves are freaking HUGE, and it's not muscle, it's fat) and simply won't tone. I also used the elliptical machine almost every single day at the gym this past summer, and for two years before this I walked all over campus, which was also a few miles a day.
What am I doing wrong? Or is my fat just covering up the muscles?