The drills this week are intended to help you relax your forearm during the recovery phase of the arm stroke. Finger Drag (FD) should be done with the tips of your fingers trickling through the water but with the muscles in your forearm Completely relaxed. Then the Catch Up (CU) with Zip Ups drill re-emphasise that, as you drag your thumb up the side of your body with the same relaxed forearm.
From there we're immediately into a Lactate Tolerance set, 2 sets of 6 x 50m really hard with a 50m recovery between the sets. Do these at your hardest sustainable pace.
The main set practices negative splitting, bringing back a race at a harder pace than you start. The hard effort increases in distances as the set progresses, try to keep these efforts higher than the steady effort but not flat out.