Complete 3x 20s with 5:00 recovery in between and take the average.
Followed by 2x 13:00 recovery…
True power is usually generated within 7-12 seconds, once you go past this stay strong for the duration. Looking for 2 numbers during effort, the MAXIMUM amount of power produced and the AVERAGE amount of power produced. Every effort should be maximum, there will be fade, that's normal. Stroke rate will be higher than normal, but the speed in which you generate the power in those working seconds needs to be quick, still focusing on correct posture and movement patterns, do not shorten anything remain long and strong.
2x13' @ 55% - use this as active recovery and skill/technique development.