20 Minute Hill Climb from @darkhorserowing 
5 strokes on // 5 strokes off
10 strokes on // 10 strokes off
15 strokes on // 15 strokes off
20 strokes on // 20 strokes off

Then head back down the ladder...15//15, 10//10, 5//5 and back up again until the 20 minutes are up. 

Held a 22 stroke rate for the "on" pieces. Set the drag to 112.