How To Test Your CSS Pace

  • Warm up adequately in the pool so you are ready to swim fast.
  • Complete a 400m time trial starting from a push not a dive and record your time
  • Rest as much as you need after the 400. This should be long enough to fully recover from the 400 and be ready to give an all out maximum effort on a 200m time trial.
  • Complete a 200m time trial starting from a push not a dive and record your time.

Take your 400 and 200 times and plug them into the CSS calculator. The calculator will show you your new CSS Pace. Train at this pace to develop your Swim Fitness for better triathlon swims!

What Is CSS?

CSS stands for Critical Swim Speed – the pace at which you’d currently swim a 1500 Time Trial (in yards or metres). It’s nothing complicated, just a useful baseline for endurance swimming events of 400 and above. Here’s why:

The Benefits of CSS Training

  1. CSS is like tempo training for biking and running - it's a pace that’s tough enough to develop your aerobic capacity but not so hard that it’ll take you days to recover. 
  2. CSS is a specific to endurance swimming (400 and longer). It may not make you the fastest 50 or 100 swimmer, but it will train you to sustain a moderately high speed for longer distances.
  3. You will develop your pace awareness the hard way (which is usually the best way!) Start out too fast and you’ll pay the price later. CSS intensity usually feels easy in the beginning and then builds as the shorter rest periods start to accumulate.
  4. CSS Testing spares you the pain of a 1000 or 1500 time trial. Trust me, those aren't fun.
  5. Once you know your CSS pace, you can use a Finis Tempo Trainer Pro to help you train. It’s a small underwater metronome that can help you keep pace in your CSS-focused workouts.

CSS Sample Workouts

Once you’ve worked out your CSS pace, the training possibilities are endless. You could start off by trying these four simple workouts. You can shorten them if you’re not quite ready for 2000 metres or yards yet. Don’t forget to include a warm up (400-800m/y) and warm down (100-200m/y) too.

1.       20 x 100 with 15 secs recoveries. All at CSS

2.       10 x 200 with 20 secs recoveries. All at CSS

3.       5 x 400 with 30 secs recoveries. All at CSS

4.       3 x 600 with 45 secs recoveries. All at CSS

Conclusion: Why CSS Training?

CSS-focused sets help improve your sustainable speed over longer distances and enhance your pace judgement. You still need to strike a balance between working on technique, speed, CSS/threshold, endurance and open workouts to meet the needs of your target races.