I like our distance sets to also include some technical focus. This set seemed to do the trick. The “Deep Practice” points of emphasis correspond to the 1st, 3rd, and 5th 50s of the 300. The swims written in black are meant to be descending effort (getting faster) on an increasingly tighter interval. At the end of the set, we recorded 10-sec heart rate values for swimmers immediately upon finishing 30 seconds after finishing, and 60 seconds after finishing. B3 = breathing every 3 strokes. This set was performed in a SCM pool. 39-43 minutes, 3,000m.