Here’s a subtle way to introduce some speedwork.
If you’re a runner, you may have done fartlek or "speedplay" as part of your training. On a typical fartlek run, you might cover 5 to 8 miles at an easy pace, with short bursts of speed thrown in every quarter mile or so. This set uses the same idea.
16 X 25 on a sendoff that gives 15 to 20 seconds rest
Alternate 3 X 25 easy swimming @ max distance per stroke and 1 X 25 controlled SPRINT holding good form
8 X 100 choice (but not IM), on a sendoff that gives 20-25 seconds rest
The easy lengths should be very easy and aerobic. The FAST lengths should be at 85 to 90% effort. Try to build into the FAST lengths by accelerating slightly from the flags into the wall just before each fast length.
#1: last 25 is FAST
#2: 3rd 25 is FAST
#3: 2nd 25 is FAST
#4: 1st 25 is FAST
#5: last 50 is FAST
#6: middle 50 is FAST
#7: first 50 is FAST
Take an extra 30 seconds rest
#8: full 100 is FAST (time it!)
100 easy pull as recovery
1 X 50 choice (fins optional); build to FAST on the entire 50. You should be building speed and accelerating from the flags INTO and OUT OF the turn.
2 X 25 choice (fins optional) with a turn. Build each 25 to RACE PACE. Accelerate into the turn.