Interval Time. 4x20secs rest 1:30' complete 3 rounds with 3' rest between Every 20seconds you are trying to produce the maximum amount of power possible. There will be fade, that's natural. Keep movement patterns the same, try not to change them and pump up the resistance a little, around 20 extra drag factor. Remember 7-12 seconds to generally hit peak power. You are looking for the highest wattage you see for the effort.