Critical Swim Speed
As you are trying to level up your swimming you have probably come across the terms Critical Swim Speed (CSS) or Threshold Pace but may not know what they mean or how to figure out what yours is. Don’t worry we have you covered! Below find out what CSS is, the test set you need to do to figure it out and our handy dandy calculator that will actually calculate your CSS or threshold pace for you! If you already know all this and just want to use our calculator, just scroll to the bottom and plug in your times!
What is Critical Swim Speed or Threshold Pace?
Critical Swim Speed (CSS) is the theoretical fastest pace that a swimmer can hold continuously without exhaustion. It is essentially an approximation of your lactate threshold speed.
Why Should I Care About CSS?
If you are a distance swimmer, open water swimmer or Triathlete then improving your aerobic capacity is a key factor in making you a faster swimmer. Obviously technique is a high priority but that only takes you so far. Once you have mastered technique then you should really care about CSS…a lot!
Improving your speed at threshold pace will lead to drops in your race times! That is the entire reason why you train…to swim faster in your races. Doing anaerobic speed work is important but it won’t necessarily make you faster over the course of a distance swim.
Critical Swim Speed or Threshold Training should have you focused on swimming at your threshold or CSS pace but with short rest periods between each swim. Training in this way allows your body to develop your aerobic system. This is exactly what you need to become a better distance swimmer.
This is may feel like an odd concept for many of you with traditional competitive swimming or masters swimming backgrounds. Generally in those environments the training is much faster paces with longer rest periods as opposed to this slightly slower paced swimming with short rest intervals. Keep in mind that most races in the competitive pool swimming world are less than 500 yards or 400 meters. You are a distance swimmer now, so it is time to train like one!
Test Set to Find Your CSS
The CSS test is not very complicated but when done right it will hurt! You will do two time trial swims. First you will do a 400 yard/meter swim. Then do some easy swimming or rest to fully recover. Then you will do a 200 yard/meter time trial. It is essential that you do a solid warm up and a build set so that you are ready to rock these two time trials. These time trials should be started by pushing off the wall and not diving in from the blocks! Don’t forget to write down your times for both the 400 and 200 yard/meter swims!
Your goal should be to pace each time trial evenly and not to start fast and then die on each one. Once you have finished your test, take your 400 and 200 times and plug them into the pace calculator below to find out what your CSS pace is that you should be training at to improve your swim.
Your CSS pace will change as you train so it is important to do this test every 6-8 weeks to find out your new training pace and to see all the improvements you are making!
Critical Swim Speed Pace Calculator
Pool length:Your 400 Time
Your 200 Time
Your CSS Pace: /100
We hope you found this information helpful and are considering making the switch from traditional training methods to more threshold pace training. If you have any questions, please reach out to our coaches any time! We have a few different free resources for you to help you apply these new findings to your training.
Check out our article on how to write your own CSS based workouts. Additionally if you need a few more ideas, we have an article with FREE pool CSS workouts and one with FREE open water CSS workouts. It is time to start getting faster today!We also have very FREE online training programs that you can use to do on your own! All of them are CSS based workouts to help you improve your aerobic capacity to make you the best distance swimmer or triathlete you can be!