This is the first of a series of practice samples I will post that are intended not only to “grow brain cells” but to prepare me for an English Channel swim.

Standard marathon swim training calls for long hours, long repeats, and long sets. I will do some lengthy training sessions — up to six hours in open water — but I think there’s also a place for short, acutely-targeted, practices and sets that aim more for precise execution than tedious repetition.

In fact, for me this is a necessity. Because of a neurological condition – arthritic narrowing in my lumbar spine – I tend to get foot and calf cramps after less than an hour of swimming. So I need to program my pool practice to wring maximal value out of minimal time. The best way I know to do so is with a focus on training my nervous, rather than aerobic, system.

Traditional swim workouts include standard ingredients, such as a warmup, kick set, pull set, main set, sprint set, perhaps a “technique” set. What they have in common is a focus on how far and how hard. Often, there’s filler – included to “get the yards in.” Sometimes, without much irony, it’s even called garbage yardage. A leading goal of this kind of training is to “grow new capillaries” which are microscopic blood vessels.

My practices are explicitly designed to grow new brain cells instead. “Capillary beds” still get improved, but that’s just incidental. What’s explicit in my practice planning is a series of tasks that build the skills or habits that make a difference in my open water races. I also design most sets to include a means of measuring how efficiently I complete each swim. Finally, my sets or tasks require strategy to be completed successfully.

The key to training this way is to design training sets as empirical experiments in efficiency. This requires at least two kinds of data on each swim to measure how effectively I swam. A combination of SPL (Strokes Per Length) and time; of SPL and SR (Stroke Rate, with the aid of a Tempo Trainer), or SR and time.

Most swimmers only know the final time for a repeat – by looking at the pace clock when they finish swimming. I always know how I constructed that time.

I don’t always begin a set with a specific goal in mind. Usually I just do the first swim moderately, then use my time and SPL as a benchmark on subsequent repeats. I always set a strategy for improving on the benchmark throughout the set. Measurable results and a strategy for improving them are the key elements to effective training and to growing brain cells as well as capillaries.

In a series of posts I’ll share examples from my practice.

Friday Dec 11 2200 yards in 38 minutes
This was my first pool practice in 10 days, a week of which was spent in San Francisco – where I swam in the 52-degree Bay but not in a pool. So I was feeling a bit rusty as I started. Also only 38 minutes remained of open swim when I got in, so I decided to swim a single set of 7 x 300 on 5:00.

Doing a practice which consists of only one extended set isn’t unusual for me/ As noted above, I can only last about an hour in the pool, so I try to spend every minute on activities that directly aid improvement. I usually start with a gentle pre-set, but because I started right in on the main set, the first few 300-yard repeats effectively became the warmup.

Starting directly with the main set helps reveal the details of how a swimmer’s body responds to warmup. Physiologists say warmup prepares the circulatory system to deliver more oxygen to the muscles and the muscles to consume more oxygen. But that doesn’t convert automatically into faster swimming. The only guarantee of faster swimming is to improve Stroke Length and/or Stroke Rate. So I’m curious about what happens to those during warmup.

I swam #1 in 4:22 (4 min, 22 sec). I hoped to maintain 14SPL but within 100 yards was taking 15SPL then 16SPL near the end. My stroke felt slightly ragged (an effect of “neural rust”?) and thus not resistant to the slight increase in fatigue that follows the first few lengths of any swim.

On #2, I swam no harder — in fact I felt a bit easier – but my time improved to 4:17 and I held 14SPL for the first 200 yards. Why did my Stroke Length hold longer and why did I swim faster? Mainly my stroke felt a bit more “tuned” – I felt noticeably more precision in my movements and timing. That allowed me to cover 300 yards in 5 fewer strokes. And since each stroke takes about a second, I saved 5 seconds from #1.

On #3, again I didn’t increase effort, but held 14 SPL for the entire distance and improved another 3 seconds, to 4:12. Again I saw a direct link betweenstrokes saved and seconds saved;- it took 3 fewer of each to complete the 300. Once again, I experienced a bit more “mojo” in my swim, reflected mainly in a slight, but noticeable, improvement in my sense of integration – arms, legs and torso more in synch.

The takeaway from the first 3 x 300 is that the primary benefit of the warmup period might be more in neural tuning than in the physiological effects that usually get the credit. At least that seems to be the case for me, a reflection of my focus on creating neural adaptation with my practice.

After improving my times while lowering my stroke count over the first 3 x 300, I sensed I had wrung all the improvement I might get out of that strategy, and decided to go the other way – increasing stroke count — on the final 4 x 300. On #s 4 to 6, I would start at 14SPL, then allow myself one more SPL at a pre-selected point.

On #4 I held 14 SPL for the first 250, then increased to 15SPL on the final 50. My time was 4:09, improving by 3 seconds while adding 2 total strokes.

On #5 I held 14 SPL for the first 200 and increased to 15SPL on the final 100, adding 2 more strokes, and again improving by 3 seconds to 4:06.

On #6 I held 14 SPL for the first 150 and 15SPL on the final 150, adding 2 strokes once again – and again I improved by 3 seconds to 4:03.

Over 3 x 300s, I had, in essence, “traded” 6 strokes for a 9-second time improvement. In fact, over the first 6 x 300, I had dropped a total of 19 seconds – but my stroke count was still lower than it had been on #1! At no time had I consciously tried to either “go harder” or “swim faster.” At all times, my instructions to myself were process-oriented – a focus on how I executed my strokes. This is what I mean by a strategic approach to swim training.

On #7, I took 13 SPL on my first length, then held 15SPL for the next 11 lengths. I also switched from bilateral breathing, which I had done up to that point, to breathing left all the way, as I usually do at the critical point in my races. My time was 3:58. This was also the first 300 on which I felt physically taxed. It took enormous discipline to hold 15 SPL on the last few lengths.

How does this very brief practice – 2200 yards and 38 minutes– relate to the 22 miles, and possibly 14 hours it may take to cross the English Channel? Though my practice was brief, for the entire time every cell in my body was organized around getting as much as possible out of each stroke, with the least possible effort. The exacting nature of the task I set myself – and the unblinking focus required to complete it – are also good training for the mental stamina which I believe is even more important than physical endurance in Channel swimming.