Many of our swim workouts look something like this:



When you see that, you're supposed to do all three of the main sets, with a short break in between sets. If you don't have enough time at the pool to do all three, you can drop one or two of the main sets (drop #3 first, then #2).

However, we don't recommend dropping sets on a regular basis or you will find you aren't as prepared for the swim in your race(s) as you could be.