SuperFly Coach Eric offer up one of his go to swimming workouts for athletes of all distances. With a little modification it can be made to fit whatever your training for and is a great balance of speed and endurance.
This workout is very simple, and if you are one of my athletes you have no doubt seen it before. I call it "Oh Oh's and 25's" not because it is going to make you cry or anything, but because the 00 section is easily capable of being modified to fit whatever your training for.
Start with a good simple warmup, typically I have my athletes do 100 swim, 100 kick, 100 swim and then 4*75 build by 25 so each 25 in the 75 is a little faster than the previous, with the fastest one being about 85%.
The main set is the part we can play around with and it simply looks something like this:
4 times through: no extra rest between rounds
300 @70.3 effort R:30
4*25 FAST R:15
The 300 is the part I refer to as the "Oh Oh's". This part you can move around based on what your training for or how deep into training you are. If you are an Ironman athlete, deep into your training cycle maybe you want to do 500's for this workout for 1 week, 600's the 2nd week and 700's the 3rd week but you'll leave the fast 25's at 4 no matter how much distance you want to do. Typically for Ironman athletes I don't go over 800's for the main set, if you get that high in yardage, try starting back at 600's and pushing the pace to make them faster instead of longer.
If your training for a 70.3 you might want to start with 500's the first week, 600's the second and 700's the third, but the great part of this set is you can start wherever you want. If you're just picking up the season, don't be afraid to start with 200's or 300's your first couple weeks back in the pool.
I also love this set cause it's simple. If you're a road warrior and on the go a lot it's an easy set to remember and knock out without much thought and you don't have to bring a piece of paper or your cell phone onto the pool deck, but it's also a great balance of speed and endurance to build your overall swim speed.
The whole workout might look something like this, knowing that the "oh oh's" section is customizable to fit your swim need.
100 swim, 100 kick, 100 swim
4*75 R:15 build by 25
4 times through, no rest between rounds
400 R:30 @70.3 effort
4*25 R:15 FAST
Warmdown as needed
Eric Turner is a coach for SuperFly Coaching, Element Multisport Ambassador and a regular contributor to the Element blog. You can learn more about him at SuperFlyCoaching.com/Eric