A comfort swimmer's guide to easy swimming

As my shoulder becomes stronger and I am able to swim pain free I have been gradually adding some sprint work into my workouts. Today, for the first time, I chose one of Leslie's HIT workouts and did a modified version, mostly shortened the total workout to fit the time I have available to swim. It went well but I am definitely in need of more speed work. My "fast" swims, especially backstroke, were a bit off what I should be doing.

Warm up (900)
500 choice - swam as 125 free/125/back/150 free kick/100 back kick
1 x 100 scull :20 SR
50 EZ
8 x 25 shooters w/fins @ :45 - alternated dolphin on back with face down dolphin kicking
50 EZ

Main Set (1900)
8 x 50/1:15 kick - 1-4 w/board & snorkel, 5-8 on back, all between 55-58
1 x 100/2:00 negative split - free, went 1:15
1 x 200/4:00 DPS free w/paddles - w/freestyler paddles, 14-15 SPL

6 x 50/1:15 kick - 1-3 w/board & snorkel, 4-6 on back, all between 55-58
1 x 50/1:30 fast @ 100 pace - back, went :38 (more like 200 pace on this one)
1 x 100/2:00 negative split - back, went 1:23
1 x 200/4:00 DPS free w/paddles - w/ freestyler paddles, 14-15 SPL

4 x 50/1:15 kick - 1-2 w/board & snorkel, 3-4 on back all between 55-58
2 x 25/1:00 AFAP - fly, went 17
1 x 100/2:00 negative split - free, went 1:14
1 x 200 DPS free w/paddles - w/ freestyler paddles, 14-15 SPL

Warm down
100 EZ

Total: 2900 yards