I was Dx with pd 3 years ago and on Sinemet 3x a day. I am a follower of John Pepper's fast walking and walk 2 or 3 days a week. Normally, I go to gym or take fast walking one or two hours after taking Sinemet. I usually walk about 4.5 km in 55 minutes. The first 1.5 km, I am walking normal with slight limping on my left leg which is my weaker part of the body. Then, my left leg starts dropping slowly for about 2 km and gain strength again but not fully charged for the remaining walk. Last week, after 30 minutes of having Sinemet, I started walking and found that first 3 and half km was amazingly good. Then, all of a sudden without any sign, my left leg dropped and started shuffling. It was like switching off instantly. I wonder why? Has anyone experience this?