Hi, Carrotgirl, do not worry too much. I experienced a lot of pain on legs and joints during the juice fasting. After the fast,I feel so much flexible on my joints. I can stand up for a very long without feeling any pain.
You must be sure to drink enough liquid (juice+pure water) and have BM every day.
Now it is end of my day 4, I have headache all day long and start feeling pain here and there. It is a learning journey and you will become more confident and know more about amazing healing power of your own body.