For about 5 years I was on the plate for 10 minutes at maximum speed (50)--this machine was in the health food store owned by my best friend. I have since bought my own machine, cost was about $250. They have come down in price over the last couple of years and can be bought for about $150. The one I bought has a maximum speed of 99 and runs for 15 minutes. I'm not sure I was getting any stronger vibration than the original machine at 50. There is no explanation as to what these numbers mean. Is this the velocity of the vibration mechanism measured by some engineering terminology? I don't know.