Metrics That Matter: A Model For How You Can Measure Swimming Improvement
by Total Immersion
The following post was previously published by Terry Laughlin on May 10, 2010.
There’s a saying (perhaps from statisticians?): “What gets measured gets improved.” Because I aim to improve my swimming in every practice, I plan them with metrics that tell me – empirically – how I did. In most sets I use the first repeat or two to establish a “baseline,” which I try to improve upon as I go. My metrics include:
- Distance of repeats and/or the set
- Strokes Per Length [SPL]
- Time for the repeats, and/or
- Stroke Tempo (in strokes per second) from the Tempo Trainer.
In addition to the objective numbers above, I also include a subjective rating, for effort level or “mojo.” I’ll describe how I use subjective ratings in another post. Here, I’ll focus on how and why I use hard data, with examples from 3 different practices.
Last week I traveled to Pittsburgh, Thurs through Sat, to conduct a clinic for the Allegheny Mountain LMSC. While traveling, I try to swim as regularly as possible, though sometimes I can only squeeze in 30 minutes or less, as was true two of the three days I’ll recount here. As you’ll see, even 20 minutes can constitute a great practice when you aim for measurable improvement.
Thursday May 6 1000 yards at Bucknell University
While driving from New Paltz to State College, PA, I stopped in Lewisburg for a swim and lunch with Jeannie Zappe, a TI Coach. We had only 20 minutes to swim. I suggested 20 x 50 on a minute, trying to gradually increase pace, while maintaining a constant SPL.
On the first 50, swimming with consummate ease, I took 25 strokes (12 down, 13 back) and 46 seconds. My goal would be to continue taking 25 strokes per 50 for as long as possible while gradually swimming faster. This is a common set for me; I always try to let the seconds “melt away” (swim faster without trying) initially. When I succeed, it’s because my nervous system gets progressively more “tuned” to the task.
Over the first 10 x 50, I improved gradually from :46 to :42 with no perceptible increase in effort. My primary focus was to feel a longer, more slippery bodyline. When the effortless improvements no longer came, I increased effort in highly specific ways:
- More sense of hold with my hand and forearm.
- More snap in my 2-beat kick “toe flick” – yet keeping it streamlined within the “shadow” of my upper legs.
Over 6 x 50, I improved to 39 seconds. During my final 4 x 50 I allowed myself 1 more stroke on each length, for 27 total, and improved to 38 seconds, trying to feel a bit more ease at that higher count and faster speed. I felt great at the end.
What happened? To maintain the same SPL for an extended series of repeats, I have to travel a constant distance on each stroke. To improve pace, I have to propel myself over that distance faster. That means the frequency of my strokes also increases – though I never consciously tried to stroke faster. So Stroke Length was constant. Stroke Rate increased . . . because Velocity increased. This is different – and easier – than trying to stroke faster . . . which is the most common way to try to swim faster.
Friday May 7 4200 yards at JCC in Pittsburgh
Suzanne Atkinson brought me to the JCC where she’s a member. We swam for about 90 minutes. For warmup, I swam 400 easy, alternating 25s of FR, BK and BR. I held 13 SPL for FR, 16 for BK and 8 for BR. I can take fewer strokes on back and breast if I focus in an exacting way, but preferred to stay relaxed.
Main Set: 6 rounds of 4 x 50 + 2 x 100 + 1 x 200 with Tempo Trainer. Increase tempo by .02 sec on each round, progressing from 1.10 sec/stroke on 1st round to 1.00 sec/stroke on 6th round. I rested 10 beeps between 50s, 15 beeps between 100s, 20 beeps before the 200 and gave myself a minute between rounds to reset the TT.
My SPL on the 4 x 50 @ 1.10 was 14+15. My goal was to progress through all distances and rounds to the final 200 @ 1.00 with as little change in SPL as I could manage. I was able to keep my SPL at 16 or lower for rounds 1 through 4. In round 5 (1.02 sec/stroke) I had perhaps 3 lengths (of 24 total) at 17 SPL. In round 6 (1.00 sec/stroke), I took 17 SPL on about 6 lengths.
Suzanne and I finished with twelve 25s of Butterfly.
What happened? The goal of this set is to swim constant pace within each round — as repeat distance goes from 50 to 200 – and to improve pace with each successive round. If Tempo and SPL stay constant, so must pace. If Tempo increases and SPL stays the same (or increases very modestly), then pace improves. If SPL increases too much as Tempo increases, then pace will stay the same, or possibly even get slower.
I only checked the pace clock after the 200s. My 200 time improved an average of 2 seconds in each round. That means a tempo increase of .02 sec for one stroke created an improvement of 2 seconds (100 times as much) for 200 yards. This is a decent “trade” of tempo for speed so I ingrained good efficiency habits during this set.
Saturday May 8 2200 yards at Duquesne University
Duquesne Coach Dave Sheets opened the pool so Suzanne and I could swim prior to our clinic. He also joined us for the swim (and was impressively fast; in fact, his backstroke repeats were as fast as or faster than my crawl.)
We had only 30 minutes, so I planned a set similar to Friday’s, but with a varying pace emphasis with each round, in place of Saturday’s constant pace emphasis.
Main Set: (1 x 200 + 8 x 25) – (1 x 200 + 4 x 50) – (1 x 200 + 2 x 100) – (1 x 200 + 4 x 50) – (1 x 200 + 8 x 25) The 200s were to be swum at “Cruise” pace and the 25s, 50s and 100s at “Brisk” pace. I aimed to hold ALL repeats @ 14 SPL.
I didn’t time the 200s, focusing instead on a Stroke Thought of Superslow Recovery without sacrificing balance or stability. I swam the 25s in an average of 17 sec, the 50s in 37 sec and the 100s in 1:14-1:15.
What happened? SPL remained constant, but – as on Thursday’s 50-yd repeats – pace varied. I swam significantly faster on the 25s, 50s and 100s, than on the 200s. In this case, I did put a good deal more effort into them. But SAME SPL combined with FASTER Pace also means higher Stroke Rate. This time I accomplished faster pace by shortening repeat distance and adding a bit of effort.
In all 3 practices I created nervous system adaptation by varying the task, while keeping at least one variable constant.
- On Thurs, repeat distance and SPL stayed constant, SR (and consequently, pace) increased.
- On Fri, I tried to keep SPL constant, and succeeded in minimizing change as repeat distance and tempo increased.
- On Sat, I kept SPL constant while repeat distance varied. Pace and SR changed as repeat distance got shorter.
When I describe my practices, I’m often asked how I can remember so many details to record them in my log later. Part of the reason is years of “data collection and recording” have trained my brain for this kind of memory capacity (which is highly specialized; outside the pool, I’m known for being absent-minded and forgetful). But recall is also made easier by the fact that I have a context or framework for the numbers I track. I use my first repeat or two to set a baseline or benchmark– then I decide, based on experience, what sort of improvement goal I’ll pursue. Since thousands of hours of practice have improved my ability to execute what I intend, I usually need only to take note of where I’ve diverged from the plan.
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