With the resistance gauge thing up to 10. 20 strokes on (ie full pressure) at rate 20, then 22, 24, 26, 28, 26, with 10 strokes off (light pressure, whatever rate you like) between each 20 strokes.
In the last 10 strokes rest turn the resistance thing down to 1, then repeat pattern at rates 26, 28, 30, 32, 34, 36. Repeat. ie you do 20 strokes on then 10 strokes off then 20 strokes on etc all the way through. The purpose is to get your split as low as pos on the first high resistance set, then in the low resistance set the split matters less (although it should be pretty low) but the speed with which you pick up the catch and draw back is paramount.
Do not belt it up the slide to get the high rates - try and be ultra quick in the draw and slower up the slide. Do not rest between part 1 and part 2, instead rest after you have done part 2 for a few minutes and then start again. Write down the distance you go for each block (part 1 and 2 together).