Many of you are probably familiar with the TI Green Zone chart--a height-indexed chart of efficient stroke counts for 25y, 25m, and 50m courses. If you haven't downloaded it yet, it's available on the Free Stuff page
at the TI Store.
While in St John USVI for the TI Open Water Experience, Coach Chris Douat (1st TI coach in France) and I were discussing those charts and both of us agreed that they could be more precisely individualized. We came up with a way of doing that, using Tempo Trainer. The exercise is to work through a range of tempos of about .2 seconds (.95 to 1.15, 1.0 to 1.2, 1.05 to 1.25, 1.1 to 1.3, etc.) and find out what happens to your stroke count.
I decided to perform this experiment as soon as possible. Following the OW camp I flew to South Florida to co-direct a 1.0 Coach Certification Course with Coach Suzanne Atkinson. While there I swam sets of 50m repeats in the Coral Springs Aquatic Complex 50m pool on two consecutive days.
Both days I started at Tempo 1.3 and swam 32 x 50, finishing at 1.0 Tempo (I repeated 1.0 twice). I counted strokes on all 50s. I considered the first 10 as a tuneup and treated the 50s between 1.2 and 1.0 as where I was likely to achieve my personal Green Zone.
On Monday my SPL was 38 at 1.2 and 42 at 1.0.
On Tuesday I did a little better, swimming 38 SPL at 1.2 and 41 SPL at 1.0.
According to the chart my Green Zone should be 36 to 44, but I think this narrower range is probably more accurate. I could probably continue to .95 Tempo and be between 42 and 43. So the right range for me to determine Green Zone is probably .95 to 1.15. I'll try that soon.
Today, back in New Paltz I did a similar set in a 25y pool. Rather than 50s, I swim a series of 27 x 100 repeats. I started at 1.3, treated the first 7 x 100 as Tuneup and began tracking my stroke count closely when I got to 1.2.
At 1.2 my SPL was 14 (56 strokes for 100y). I reached 60 strokes (15 SPL at 1.13) and didn't reach 64 strokes for 100y (16SPL) until 1.02. I was at 61 strokes for 1.01 and 1.0.
According to chart my Green Zone is 14 to 18 SPL, but I've gone with 13 to 17 in training.
I'll try this again soon, working my range from 1.15 to .95.
I'd love to see other curious swimmers try this and post your results on this thread.
Pls include your age, gender, and height to help us better categorize/analyze the data we collect.
I'm 64 y.o. (65 in two months), male and 6'0" tall.