Medium - 10,000m with rate changes every 2000m: 22-26-22-26-22
Row for a total of 10,000 meters at a sustainable intensity, varying your stroke rate as follows: row 2000 meters @ 22 spm, 2000 meters @ 26 spm, 2000 meters @ 22 spm, 2000 meters @ 26 spm, and 2000 meters @ 22 spm.
Check this Concept2 workout on the ErgZone app: