Row Conditioning 
10 minutes w/up & steady rowing.
30 seconds reset
5 minutes @19 spm + 10 strokes each minute @24, 26, 28, 26, 24.
30 seconds off
5 minutes @19 spm + 10 strokes each minute @26, 28, 30, 28, 26.
30 seconds off
5 minutes @19 spm + 10 strokes each minute @28, 30, 32, 30, 28.
2 minute cooldown

Focus on strong consistent strokes, even at r19. This workout tests your recovery after a maximal effort. Expect your heart rate to take about a few strokes to settle especially after the higher stroke rates and try not to treat the r19 work as a recovery period.