I have only recently started cycling and am using Rouvy with a Derito X smart trainer. What I am confused about is : If I do the approx 7 mile rides round London, Paris or other relatively flat rides I average about 13-14 mph and about 83-87 watts. The max power registered is always in the 100s - up over 200 at times. However. if I do a 'Workout'r and set the paoer bit to 90 watts I find myself almost falling off the bike after about 15 minutes. The full ride is 60 minutes . I have reached 20 minutes once but generally surrender after 15 minutes. Why the difference between the 'Workout' ribe and the 'General' ride. Allen