At Swim Smooth, one of the things we're most pleased about is how many people are using CSS to improve the training side of their swimming preparation*. We've heard from so many of you about how you've taken 5 or 10 seconds per 100m off your swim times after just a couple of months of CSS training - which is fantastic!
For more about CSS and see the calculator here: www.swimsmooth.com/training
One of the most common questions we receive about the CSS calculation is that if you keep your 400m pace the same but get faster over 200m then your CSS pace actually gets slower! This seems quite counter-intuitive that you are getting faster and yet your CSS pace is getting slower - in fact we get a lot of emails from swimmers (and coaches) telling us the calculator is broken and we need to fix it in a hurry!
The calculator is actually right though and is just telling us something interesting about fitness which is very relevant to how you should train. The calculation looks at the rate of drop-off between your 200m and your 400m times to predict what you would do over a longer distance closer to CSS pace (e.g. 1500m). So someone who is very quick over 200m but dies a little over 400m will have a slower CSS than someone who is much more evenly paced, even if the first swimmers times are quicker combined.
Mind bending isn't it? What the test is assessing is whether your current fitness is more attuned to sprinting or distance swimming. If you have a large drop off in pace from the 200m to the 400m then this suggests you're more sprint-based and you will be significantly slower over 1500m. If you have little drop off between the 200m and 400m then you're well trained for distance swimming and you will be able to swim 1500m at only a slightly slower pace than 400m.
If you think about it, this has to be the case otherwise the best sprinters in the world would also be the best distance swimmers in the world and vice-versa. You can see this explained more visually here:
Of course if you're a triathlete or open water swimmer then you are aiming to be fast over longer distances - developing your diesel engine. If your CSS is getting slower it could be you have been inconsistent with your training or you could be doing too much sprint training (very fast with long recoveries) and not enough CSS type training (not quite as fast but with short recoveries).
Example Athlete: Michael Japp
Michael has improved both his 400m and his 200m times since May, which is great news. However, his CSS has slowed by 1 second per 100m - how so? Michael improved his 400m by 5 seconds but his 200m by 7 seconds. As the 200m is much shorter, this means his speed improved relatively much more over 200m than 400m which is symptomatic of biasing training towards very fast, short intervals with lots of rest and recovery rather than longer intervals at around CSS pace.
In Michael's case being of a very strong athletic background we felt that his anaerobic system has come back to life a little quicker than his aerobic endurance and recommended more CSS training and even some "tough love" Red Mist endurance sets: www.feelforthewater.com/2012/07/red-mist-set.html
Gaming CSS
There's even been some discussion recently about how you can "game the test" in order to get a better CSS result. You might do this by swimming deliberately slowly over the 200m which would give you a better CSS pace but this would be totally pointless as the whole idea of the test is to get a real picture of your current fitness so that you can train accurately going forwards.
Gaming the test will only see you having to target unrealistic CSS target times in training which will ruin the quality of your training - so please don't do it! Both the 200m and 400m time trials have to be maximum effort but they still need to be well-paced to yield your best times. This in itself can be confusing - how can an all-out effort be well paced? See our classic Gradual Crescendo post here: www.feelforthewater.com/2013/05/the-gradual-crescendo.html
Swim Smooth!
* Swim Smooth didn't invent the CSS calculation but we are huge fans and advocates of using it to help swimmers train better. To improve the accuracy of this training try doing it in conjunction with a Tempo Trainer Pro to set your training paces.
For more about CSS and see the calculator here: www.swimsmooth.com/training
One of the most common questions we receive about the CSS calculation is that if you keep your 400m pace the same but get faster over 200m then your CSS pace actually gets slower! This seems quite counter-intuitive that you are getting faster and yet your CSS pace is getting slower - in fact we get a lot of emails from swimmers (and coaches) telling us the calculator is broken and we need to fix it in a hurry!
The calculator is actually right though and is just telling us something interesting about fitness which is very relevant to how you should train. The calculation looks at the rate of drop-off between your 200m and your 400m times to predict what you would do over a longer distance closer to CSS pace (e.g. 1500m). So someone who is very quick over 200m but dies a little over 400m will have a slower CSS than someone who is much more evenly paced, even if the first swimmers times are quicker combined.
Mind bending isn't it? What the test is assessing is whether your current fitness is more attuned to sprinting or distance swimming. If you have a large drop off in pace from the 200m to the 400m then this suggests you're more sprint-based and you will be significantly slower over 1500m. If you have little drop off between the 200m and 400m then you're well trained for distance swimming and you will be able to swim 1500m at only a slightly slower pace than 400m.
If you think about it, this has to be the case otherwise the best sprinters in the world would also be the best distance swimmers in the world and vice-versa. You can see this explained more visually here:
Of course if you're a triathlete or open water swimmer then you are aiming to be fast over longer distances - developing your diesel engine. If your CSS is getting slower it could be you have been inconsistent with your training or you could be doing too much sprint training (very fast with long recoveries) and not enough CSS type training (not quite as fast but with short recoveries).
Example Athlete: Michael Japp
Michael has improved both his 400m and his 200m times since May, which is great news. However, his CSS has slowed by 1 second per 100m - how so? Michael improved his 400m by 5 seconds but his 200m by 7 seconds. As the 200m is much shorter, this means his speed improved relatively much more over 200m than 400m which is symptomatic of biasing training towards very fast, short intervals with lots of rest and recovery rather than longer intervals at around CSS pace.
In Michael's case being of a very strong athletic background we felt that his anaerobic system has come back to life a little quicker than his aerobic endurance and recommended more CSS training and even some "tough love" Red Mist endurance sets: www.feelforthewater.com/2012/07/red-mist-set.html
Gaming CSS
There's even been some discussion recently about how you can "game the test" in order to get a better CSS result. You might do this by swimming deliberately slowly over the 200m which would give you a better CSS pace but this would be totally pointless as the whole idea of the test is to get a real picture of your current fitness so that you can train accurately going forwards.
Gaming the test will only see you having to target unrealistic CSS target times in training which will ruin the quality of your training - so please don't do it! Both the 200m and 400m time trials have to be maximum effort but they still need to be well-paced to yield your best times. This in itself can be confusing - how can an all-out effort be well paced? See our classic Gradual Crescendo post here: www.feelforthewater.com/2013/05/the-gradual-crescendo.html
Swim Smooth!
* Swim Smooth didn't invent the CSS calculation but we are huge fans and advocates of using it to help swimmers train better. To improve the accuracy of this training try doing it in conjunction with a Tempo Trainer Pro to set your training paces.
