Updated my critical swim speed (CSS) today. Went to the pool to do a long day, and had been planning on doing my CSS for weeks now, but just never had the chance. So today was the day.
It has been a long time since I've done a CSS test. Like, since Moscow, and my itty-bitty 33.3 yard per lap pool. So I really needed to update it. In Moscow I had the benefit of 1/3 more flip-turns. Now that I have access to standard size pools, I need to update the times.
I have the Swimulator ap for my iPod. It's a nice little ap that let's you put in your 400 and 200 times (the basis of the CSS test) and it kicks out not only your CSS but also what you should punch in your Tempo Trainer should you want to use one for pace training...which I do.
Swimulator application
So, after a warm up of 800 meters, I did the 400. My time for 400 meters was 6:41.6. Good enough, I guess. I did some slow laps after to get the HR down to about 105, then I did the 200 in 3:15.4. My awesome little ap told me that meant a CSS pace of 1:43.09. What does that mean, you ask, dear reader(s)?
CSS is designed to give you a pace that you could theoretically hold for 1500 meters (or yards if you did the test in a SCY pool). The CSS won't necessarily be what you did the 400 or 200 in. For instance, at 1:43.09 per 100, my 400 would have been 6:52-6:53 and my 200 would have been 3:26. But, more importantly, if I hold that pace for a 1500, I should swim it in 25:46, which would be a great time for me.
Even better, the folks at Swim Smooth who came up with CSS have extrapolated the pace for longer (or shorter) events. So, after figuring out my CSS today I did 2 x 1500 at my 20K pace, which is CSS + :10/100. Like I said, the Swimulator showed me what my TT should be set for with my new CSS: 25.77 seconds per length. That would work if I were doing reps for an upcoming 1500M or 1650Y race. But I'm preparing for that crazy 26+ mile swim in North Dakota.
So instead, I set my TT to 28.27 (which would be my CSS of 1:43.09 plus :10), then when I was ready I turned it on, put it under my cap, and when it beeped I started my first 1500. Goal was to hit the wall coming out of my flip-turn just as it beeps. I managed to always be a few meters ahead of the beep. In fact for both sets I was somewhere between starting my first stroke cycle (after a nice streamlined push off the wall) and second stroke cycle when the beep sounded.
It's funny. It feels incredibly slow. But if I had to maintain that pace for, say, 20 kilometers, it would probably be perfect, maybe even a bit fast. Actually, the SS guys recommend adding :10 to :20 to the CSS for race pace training for 20K. So I could actually use more time. And for distances like 38K (English channel, or even longer, like my ND swim), they suggest adding :20-:30. As I get closer to that swim I'll do longer repeats, like 5 x 2000 on CSS + :25. We'll see how that goes.