When I first started walking, it was soooooooooooooooooo hard and excrutiatingly painful because I was so fat. There are hills everywhere around here and at work we are on top of a big hill so however I go I have to climb back up the hill. On one route there is a fence along the hill and I had to stop several times and lean on the fence, etc. And was slowly dragging myself along. For a long time now I have not needed to do that and go farther and farther distances -- over an hour without stopping, even up and down hills.
BUT recently I decided to try something new... and I am walking up the hills
backwards! I am amazed that I can do it! It uses an entirely new set of muscles. Whew!
Also, a coworker recently started walking with me who is much smaller and half my age. But she told me the other day that she went back to work and people were really surprised when she told them that to walk with me she really has to bust butt and work hard to keep up with me!!
That was so nice to hear since when I was younger and thinner I was SO competitive and it really "fried" me to have to be so slow when I started and have everyone passing me, etc. I am really enjoying my improved fitness.