I had to find an alternative form of exercise to replace running. I saw the Halfbike on instagram, researched, and bought one for my 60th birthday over two months ago. I am riding at least7-10 miles a day and averaging 9 to 11 miles an hour, getting a very good aerobic workout. I enjoy much more than running. I could not keep my wife off my Halfbike, and got her one too, so we both are Halfbiking most every day together. I highly recommend Halfbiking as a primary form of exercise.