10m warmup, building the stroke  from arms only, steadily increasing rate and pressure.
 
10m: 4, 3, 2, 1, starting 20spm @ 5K+10, up two each change
8m: 2, 2, 2, 2, starting 22spm @ 5K+6, up two each change
6m: 2, 2, 2, starting 24spm @ 5K+4, up two each change
4m: 2, 2, starting 26spm @ 5k pace, next 2m 28 spm sub 5k pace
2m: 26-28, 5K or better
1m: 28 spm, full power