A healthy Gorilla swings back and forth on the limbs and would come close to a leg shaker, but since he doesn't pollute his body, he hads no need to swing or pedal.
I like adjustable speed leg shakers and have never found one that last, they all break within a year, so I quit selling them.
Riding a bike or doing hard exercise to me would only cause more vein problems once they have started. A healthy person could do such things if they chose to, to me it is quite unnatural and I always start I was quite stupid to ride a bike when each car drove by while I was sweating and getting nowhere fast.
The only point is diet, nothing else matters until the stomach is cured and the orange juice method works for all, but all will not eat one meal per day and allow the stomach tp stay alkaline long enough to restore a lifetime of damage.