I like the synthesis of your thought process. My stroke rate is 47-52 per minute consistently hour after hour. I have played with this efficiency vs. Effacey concept as well. I have routinely heard stroke rate number as Steve M. Has suggested but agree that the length of stroke or distance per stroke is critical once you decide/realize your not racing for a record. In a 25 yard pool for example I take 12 (both arms) strokes on average or 6 single arm stroke cycles for reference.

Training under the tutelage of the legendary Marcia Cleveland, she has worked with me to develop my long rolling stroke that balances my energy output vs. Demand, especially in cold water which as OW swimmers know is the critical other deminision. Each person, it has become clear to me, now two years into marathon swimming has their own ‘heat capacity’. Coupling this with stroke rate and efficiency becomes the game in mind. During training (I personally put in 33-35,000 per week) both speed training and endurance pace work, I work stroke rate changes with very short rest intervals such as 8×800′s with internal pace to sprint work. I am learning this stroke rate modification is very helpful to deal with felling chilly in the water, slowing down when your tank is a bit empty and then speeding up once I have refueled. Since my goal is completing vs. A world record I believe this philosophy and training can be useful for the average Joe. Last summer I finished the Noston Lighthouse race right at 3 hours, in fact just a few seconds behind David Barra using this training strategy. Afterwards David and I were talking and he made an interesting observation about my swim. He noticed that I was gaining on him quickly near the end. At the time I didn’t think much of this but as my other races for the season wore on, it became clear that the training methods Marcia had me doing along with the stroke rate strategy I employ was the key factor.

http://one-stroke-at-a-time.blogspot.com/

For those interested, my blog is above. It’s not as eloguent as Terry’s but just another view of a 49 year old swimming One Stroke at a Time.

For example, it has been my observation that the higher the stroke rate, the faster the English Channel times. When I look at a Penny Dean (7:40) or even a Greta Andersen (record holder from the 1950s), their stroke rate was high (in the 80s). When I look at Petar Stoychev (6:57) or Yuri Kudinov (7:03), they are in the very high 70′s and low 80s non-stop. On the other hand, when I observe swimmers in the 10-16 hour range, their SPM pace is slower by as much as 20%. Because I have not personally observed hundreds of channel attempts, I am not sure if my data and understanding is correct, or I am totally off base. I understand there are other possible correlations (e.g., age of the swimmer, 1500-meter best time, fitness of swimmer, length of swimming career).

I think that this concept of ‘Speed in Swimming the Channel’ is interesting and needs amplification.

Obviously speed is important, but in simple terms – the faster you swim the higher is the energy consumption and thus the energy requirements. As an example: if you double the horsepower of a motor on a boat, you increase the fuel consumption hugely – for a very little gain in speed.

In human terms, the primary energy stores are those in the GLYCOGEN reserves, In an average adult, these reserves are some 70 grams, (mainly stored in the liver and in muscles). Glycogen is converted to Glucose as required and as a Carbohydrate, glucose is the main and initial energy source for most athletic performances.

It takes some number of hours to deplete these Glycogen reserves in a challenge like swimming the Channel. The reserves can be partially supplemented by careful feeding schedules during the challenge, but in most of us, the Glycogen stores are depleted before the end of the swim. At that stage a change over occurs to an energy supply mechanism of metabolism based on lipids.

This change over is associated with the well described “WALL” that marathoners and swimmers experience after a long effort of uninterrupted exercise.

There are many ways to combat this phenomenon, but it is important to determine your own individual ‘tank volume and reserve’.

That implies that it is vital to find the ‘speed’ that is best suited to your energy reserves and your metabolic characteristics.

A lot has been written on this subject and I can point you to further reading if there is interest.

OTTO