Set your monitor for a variable interval workout as follows, with no rest between intervals: 1000m, 1000m, 800m, 800m, 600m, 600m, 400m, 400m, 200m, 200m, 400m, 400m, 600m, 600m, 800m, 800m, 1000m, 1000m. Ride the first 1000m at a moderate pace, then 1000m at an intense pace, then 800m moderate, then 800m intense, and so on down to 200 meters, then work your way back up to 1000 meters in the same manner.