So what does all that gibberish mean?

Each line of the workout is considered a set. Here's a line by line explanation of the workout.

1. Warm-up. 400 Free is telling the swimmer to swim 400 meters or yards in freestyle. We'll assume meters for this example.

2. 200 Kick Hard/EZ by 25. Kick for 200m. Kick fast for 25m and then easy for 25m, alternating until reaching 200m.

3. 200 Pull. Swim 200m using only their arms with a pool bouy between their legs. No kicking.

4. (800) indicates you've reached 800 meters by this point in the workout.

5. Main set. 4x100 IM. IM stands for Interval Medley. This is the four basic strokes in order of Butterfly, Back, Breast, and Freestyle. 4x100 IM is telling the swimmer to swim 25m butterfly, 25m back, 25m breast, and 25m freestyle. Then repeat that 4 times.

6. 300 Back, Breast, Free by 100. Swim 100m back, then 100m breast, and then 100m freestyle.

7. 200 Breast, Free by 100. Swim 100 breast and then 100 freestyle.

8. (1700) 1700 meters have been reached

9. 200 Free Pull EZ rest :15. Swim 200 meters freestyle pulling, no kicking, with a pool bouy. Swim it easy and when finished rest 15 seconds

10. 4x50 on :55. Swim 50m within 55 seconds. Rest for the remaining time under 55 seconds and then start the next 50. Repeat 4 times.

11. 200 Free (85% Effort). Swim 200m freestyle fast, at about 85% of your maximum speed.

12. 4x50 on :55. Swim 50m within 55 seconds. Rest for the remaining time under 55 seconds and then start the next 50. Repeat 4 times.

13. 200 Free FAST - Target 3:45. Swim 200m freestyle fast and try to do it in 3 mins 45 seconds.

14. (2700) 2700 meters have been reached.

15. 200 Breast, Free (by 100). Swim 100 breast and then 100 freestyle.

16. 300 Back, Breast, Free (by 100). Swim 100m back, 100m breast, 100m freestyle

17. 4x100 IM. Swim 25m butterfly, 25m back, 25m breast, and 25m freestyle. Repeat 4 times.

18. (3600) 3600 meters have been reached

19. Warm down. 200 EZ swim. Swim an easy, slow 200 in any stroke to warm down. Always warm down after a long workout.

20. (3800) A total of 3800 meters were reached during this workout .