Interval Variable. 3000m followed by 1000m Rest 3' Repeat 4 times Each 3000m is held at 75%, each 1000m is progressive, so Round 1 - 90% - Round 2 - 90% - Round 3 - 95% - Round 4 - EVERYTHING!!! Everything is scalable. Start 5-10% lower if not at your 2k power output……#trainefficientperformbetter