I'm confused! Which measurement is important?
Is it the aerobic factor? Some research uses perameters of heart rate as a guide. They talk of maintaining 60%-80% of your resting heart rate (calculating rhr as 220-age)
Is it the speed of movement? The bikers tell us to do 85 revolutions per minute .
Then, is it important that this movement be exactly repeated in a guided fashion as in biking? Or should it be on uneven terrain to challenge us, as in outdoor fast walking?
davisphinneyfoundation.org/...
Check out this page.
Forced exercise is great but depends on others to help you.
Where as a program like Crossfit , dancing,boxing,or any group exercise program you just show up and do the exercise program for that day.
good luck
You do not need a tandem to achieve the FE goal of 80-90 rpm.
There's nothing in the research that shows any particular method of exercise is better than any other, as long as you burn a lot of calories. I explained more in the other thread and linked to Dr Alberts' research that failed to take into account that the "forced" method burns more calories. He even says it is not about the pedaling. More calories burned is more exercise. More exercise is good for PD. An exercise partner with fixed appointment times that you have to meet and you both religiously believe some high and uncomfortable level of RPMs is needed is all about motivation, and it's all a great idea. But the physiology of the benefit is about simply exercising MORE.
Many of us can harp on "exercise" all day long, but we know there are many who will not do it. Then comes along the cult of "forced exercise" saying the same thing, but attaching a specific miraculous methodology and gurus to it that gets all the rage like the new zumba, pilates, p90x, or crossfit. Fine. Have at it. But the main and great idea to it is that you get an exercise partner and you both believe in it, and you want to do it. What better way than a tandem bicycle in the country side, religiously shooting for a high RPM that you really don't like that much? I can't think of a better way, except sitting in front of the TV on my stationary bicycle for an hour or two each day. I don't need a partner because my brain gets into deep doo-doo if I don't do it.
"It's Not About The Bike, It is about the Pedaling". Dr. Jay Alberts
Oh, sorry, yeah, that's the title of his research paper.
I read it again more closely to see if I made any other mistakes, and I see I made a big one: he says the voluntary group (not Forced) kept the same target rate, 60 to 80%. Strangely, the voluntary group produced (exerted) 50% more wattage on the system, and show about 50% cardiovascular improvement, but he says both of these differences were not statistically significant. That's not too surprising because he had only 5 patients in each group. But somehow he was able to measure only 30% improvement in the forced group and it come out statistically significant?
Keep in mind his paper depends entirely on there being a partner on the tandem bicycle. From that paper, it's not about the RPM, it's about the partner. They found 80 to 90 RPM with the partner to be optimal (47 watts from the patient, 144 watts from the assistant).
It's strange but possible. I'd have to be able to see the full paper and review his other work before recommending the cost of a tandem bicycle. If it is all like he says, then there must be other types of "forced" exercise like competitive sports that would be better and exercise more skills than just the grip they were measuring.
The article by Dr Alberts is "It's not about the bike, It Is About the Pedaling". Google and read it. The cadence is the factor that determines success.
Not the RPM, but the assistant is what his ideas depend on. They simply found 80 to 90 RPM as guided by the assistant to be the key. Their idea is that not being able to control the rate yourself, but being required to respond to the RPM the assistant is choosing is the key.
To simulate this, I do not see why they could not program random, frequent adjustments to the RPM to keep the patient "on their toes", which seems to be where the benefits he measures are coming from.
Now I am not only confused, I am getting discouraged. When I pedal as fast as I can the gauge on my bike never hits higher than 31. Could that mean 31 RPMs ? No where near the 80s . Hopefully my gauge measures something else because I can never imagine pedalling almost 3 times as fast as I do now.
Main thing that keeps coming up in the exercise research is that it should be exercise that you enjoy.
In controlled rat research forced exercise is that which uses electrical shock at the end of a treadmill. In other words punishment for slowing down while running. Hardly a technique used with human research.
Any exercise is better than nothing.
Anaerobic exercise to increase BDNF
Studies in exercise and PD
What PwP need is regular rigorous exercise motivations NOT more levadopa
The benefits of exercise 
Exercise experiences
