Before you lay down 100km on the erg, have someone take a video of you rowing on the erg. Check out your technique. We should all know what a good stroke looks like by now.

How is your sequencing?

1) Are you getting those knees down before opening your back on the drive?

2) Are you pivoting forward and setting your back position before you slide back up to the entry?

3) Are you lunging forward to steel more length?

Better technique means more km's.