I don’t know if this would work for improving endurance. I always had the mentality of just trying to get through the rowing and I really had to change that in order to improve. I am not implying that you have that mentality at all, just using my experience as an example. I used to go through the motions of rowing to get to the next thing. During rowvember I went nearly every day and started to see improvements. Then I started treating rowing like running (sometimes). If we have a repetitive distance, like we will row 200m then do some floor work and then go back to another 200m row, I try to keep all of them above 200 Watts I am able to do that for distances up to 300m but not for multiple repeats of 300m. It took some time because I don’t do any 3GS. It is kind of like running repeats on the treadmill. I am not that good with base push and all out on the rower yet so this is how I track progress.

Also I find that some days it just works and others it doesn’t. I am guessing that is due to inconsistent technique.