Hi, I did my first Master-Cleanse in August this year. I walked everyday for 45 minutes to an hour. I had heard that you should listen to your body, which I find hard to do, but I just decided to take it easy.
I didn't quite stroll but I didn't power walk either. I used the walk time to relax. I stood up tall and took long deep breaths thinking about how all those trees around me were putting out oxygen and I was taking it in. I smiled at each person that passed me and smiled even broader to myself if they were really working hard- since I wasn't.
I felt great. Some days I walked a little faster than others but I think it was mainly about getting some oxygen in and keeping my body moving. I didn't try to build muscle or endurance, I needed to be nice to myself. (it is not fun for me to exercise)
I just started my 2nd Master-Cleanse and plan to do the same, light exercise.