Today I swam 3100m. Started at 9:35am. Pool was 29 degrees C.

500 Warmup

4x (200m FG Slide & Glide for minimum SPL, full power per stroke, then 50m open-hand for minimum SPL at 1500 pace). I held 13 SPL for all FG, and for the 50m I came in at :46 holding 12/13 SPL for each.

6x (100m TT ladder 1.30/1.20/1.10, then 50m recovery)

tempo # time    SPL held # time   SPL held
1.30 #1 1:31    14,15… #6 1:29    14,15..16
1.20 #2 1:29    15,16… #5 1:31   15…17
1.10 #3 1:28    16…18 #4 1:29    16…17

10x (25m hold 15 SPL, 25m hold 17 SPL, hold :22 pace, compare exertion level)

200m FG cool down

My objective today was to experiment with my 100m split improvement ideas:

  1. To increase power per stroke (stroke form, stroke strength, consistency)
  2. Stretch my fast tempo abilities
  3. Zero in on optimal 3D body rhythm for sprint distance


The first set for Objective #1 tired me out more than I expected it to. The idea was to create a rhythm for a low SPL while requiring me to accelerate using a powerful pull each time- I would have to both stroke and hold a low drag position at the same time. It was to work the hip rotation to arm connections. I was pleased with the 13 SPL- it was not slow but at a full aerobic effort. The 50’s showed me I could come in at a 1500 pace with such a low SPL. So I was able to achieve the powerful stroke + low drag position combination. The FG 200’s helped me imprint the hip thrust and body roll.

When I began the TT ladder I was much more tired than I had planned to be going into this set. On one hand I was disappointed in the times I achieved. For as hard as I was working I was hovering around 1:30. But on the other hand the point was to push my stroke rate comfort zone, not speed, and it served to reinforce my hypothesis that simply ‘swimming harder’ is not the smartest way to swimming faster. I can go faster by SPL control work much easier than by tempo control. Some how it re-arranges the priorities in my stroke and I work harder but gain less speed for the effort.

I had in mind to do a 3x (4×25, 100m) timed sprint set but I was drained from the TT ladder. So I got the idea to do some SPL + tempo effort comparison. I did 25m at 15 SPL, rested 15 seconds, and then a 25m at 17 SPL, while holding both to :22 seconds. There was definitely a difference in the fatigue level, yet the split was exactly the same. I repeated this 5x to control for my overall fatigue.

On the 15 SPL length I noted:

  • The front arm and recovery arm were able to relax for a moment
  • The stroke back was full, deep, stronger feeling

On the 17 SPL length I noted:

  • A lighter stroke, and a bit shallower especially at the back half
  • I felt little rest in the arms. Moving faster compelled me to keep all the muscles more tense, especially in the front deltoids and around the neck and shoulders.

It is obvious I am conditioned to swim at lower SPL and lower tempo so I can’t write it off the higher SPL as a waste of energy. I need to condition for higher tempo in general- [check out this 100m SR chart] to complement my low SPL. But the fact remains that there was more physiological work, more mechanical movement and therefore more energy being burned up to achieve the same time. More conditioning would lower my sense of strain because my neuro-muscular system would get used to it, but it would not reduce this mechanical fact- all other factors being equal, more strokes uses more energy and therefore I will tire faster.

Now back in my beginning cycling days I remember it took me a while to overcome the belief in the illusion that big gears (which result in low cadence) was cool, but it was actually those who could maintain high cadence who rode the best. Low cadence was especially hard on the knees, and in this way I think that is also a caution about too low of an SPL in the water- more force per stroke is required to pass through these shoulders. However, water being 800x as dense as air, the whole equation is different in that efficiency of shape and movement is far more important so there is a careful trade-off to be made in taking on extra SPL. Spinning fast in the air is not the same as spinning fast in the water. That extra motion comes at a high cost in drag and energy consumption- the longer the swim the more that adds up and the quicker the fuel tank will be drained.

In these sprint distances I can afford to burn fuel up at a faster rate. But if I want to develop speed that I can use in a long race as well, that speed has got to be generated from an efficient stroke and body position. So I am exploring the relationship between these factors so that I can learn how to adjust them to achieve better results. This is what I call the search for the path to “efficient-speed”.

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