I am the person who posted on 23andme about the results of forced pace pedaling. I'll try to answer each of your questions.

The program devised by neuroscientist Jay Alberts at the Cleveland Clinic is for patients to ride 40 minutes, 3/week at 80-90 rpms. His test group averaged a 35% reduction in their symptoms after 8 weeks and the benefits continued, at some level, for an additional 4 weeks. I tried to attach his research that was published in Neuroscience in Jan. 2009 but the file is too big for this site. Because I signed up to bike across Iowa and was afraid I couldn't do it, I increased the time and frequency of biking and had outstanding results.

Jay's research involved people who could not sustain that pace on their own, so he used stationary tandems. **** I can still ride on my own, so I use my road bike outside and then put it on a bike trainer inside when the weather is nasty. My sister-in-law and many others use stationary or recumbent bikes. The key is to maintain the rpms.

It appears to have slowed, or even reversed the direction of my PD. Some of that I assume is due to the placebo effect. I'm so happy that I have some control over my life again and that I could actually reduce medications instead of increasing them.

Insurance companies...I don't even want to go there.

I'm finding that many doctors are touting the benefits of exercise, but not many seem to know about the Cleveland Clinic research or are waiting for more data. I've been told that it's not helpful to put out hope for people who might not be able to participate. I shake my head on that one. On the other hand, a hospital in my area contacted me to see if I would help them set up a tandem program. I'm also interested in working with health clubs, YMCAs, etc. to set up a train the trainers program for spin class instructors so they can guide PD patients who can cycle on stationary bikes.

I was having foot cramps, that would extend to my knee, hip and shoulder. I, too, thought I would just scream. Amazingly, after a couple of weeks of cycling (I forget exactly how many), the cramps disappeared. I still get some in my toes and maybe my arch, but very seldom and they go away within a minute or two.

Re comments from imark3000:
I don't know what VE or wpd stand for. I used to cycle at 50-60 rpms until I started this program. Believe me, 80-90 rpms is Forced Exercise for me!