i don't know where you get the 80% from. its more like 100% for the first lap, 95% for the middle and then 100% from when you have to make your move at the end till the finish line. if your trying to improve in cycling you have to push your self farther than you think you can go. in Crits its try to break away a bunch of times. In cross you need to try pushing your self really hard in the beginning even if it means you die before the end. Simply put if you want to get faster you really have to make yourself uncomfortable and try going faster.