Critical Swim Speed (or CSS) is a measure of your lactate threshold without the need for invasive testing and is a great estimation of your swimming speed over a distance of 1000 to 1500m.
By improving your CSS pace you will swim faster and more efficiently at any distance above 400m. As such, we regularly monitor this marker with 2-3 x yearly CSS tests which involve swimmers in the squad doing a 400m and 200m Time Trial with about 5 to 8 minutes rest between each.
The calculation plots a line of regression (drop-off) in pace between the two distances and has been used in sports literature since the early 90s as a simple way of testing for the intensity at which a swimmer's physiology suddenly starts to accrue a massive amount of lactic acid. You can find out more about the CSS testing protocol here and also answers to some common queries about CSS testing here.
Not only does version 2 let you log your training in detail but you can also track your Critical Swim Speed (CSS) over time. See your CSS dropping and you know you’re becoming a faster swimmer.
Swim Smooth believe that every session you do should have a balance of 3 elements - technique, fitness and open water specific training. If you are swimming three times a week we suggest you hit this sort of routine:
1x Technique orientated session
1x Endurance biased session with longer steady paced swim sets
1x Quality session working on your threshold speed