How important is speed to an English Channel Swim
by Terry Laughlin

Posted on February 25th, 2010

This question came from Simon:

I have become curious about the impact of speed on an English Channel swim.  At present
I am doing 1 to 2 miles a day in the pool at around 2.1mph (yes, I time myself each swim to make sure I am improving!).

After just 5 months of training I have already improved my times and I
am sure I will improve still further but my question is how important
is speed to a crossing?  I recall Michael Oram saying that so
long as you keep plodding away you will get there (I can plod away for
hours) but how much does this add to the difficulty?  I am not just
thinking of the extra time spent in the water but more the tidal
switch and whether there is a minimum speed to avoid getting stuck
out there for an extra 6 hours when the tide switches.

My reply to Simon:

All of us who are training for a Channel swim hope to reach France in the least time possible. As you say, if you can avoid getting caught in a tidal shift, you decrease your chances of getting stuck – swimming in place for hours — with the coast of France seemingly within easy reach . . . but making no headway . . . because the tide has turned against you . So improving your speed certainly improves your chances.

The most important question to ask yourself is what is your plan or strategy to improve your pace? Timing your swims gives you information on your speed, but does it improve it?

Here are some things to think about with regards to speed (I prefer the term “pace” since speed makes us think of velocity, which  means little to those of us who can’t think in terms of a sub-10 hr swim.)

1. To move forward in the water, the propulsive force you generate must exceed to resistive force of the water. To move forwardfaster you need to increase the difference between propulsive and resistive forces. Which takes more effort – increasing propulsive force or decreasing resistive? When you need to maintain your pace for 10-12-14 hours, you need to be very conscious of the energy cost of your intended pace.

2. I’d guess that the average Stroke Rate for Channel swimmers is around 60 spm. How long it takes you to cross will be purely a factor of how far you travel on each of those strokes. If you travel half a meter per stroke, it’ll take you about 76,000 strokes to cross. At 60 spm, 3600/hr it’s a 21 hr crossing. At .6m/stroke it’s 17.5 hrs. At .7m/stroke it’s 15 hrs. Etc.

This is why I previously suggested stroke counting in training is helpful. Suppose I take 40 SPL in the 50m pool. Subtracting 6m for the pushoff, that means I’m traveling 1.1 m/stroke the rest of the way. I KNOW I won’t travel that far in the Channel, but I figure it’s better to create muscle memory for 1.1m/stroke than for .9 m/stroke during those times I can measure my SL.

At this point I’m swimming 11x/week, 7-8 sessions in the pool and 3-4 in OW. I figure that 90% or more of the factors that will influence my pace are developed in the pool.

10 Responses to “How important is speed to an English Channel Swim”

  1. OTTO THANING says:

    Hi Terry,

    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.


  2. Otto
    Thanks so much for a well-informed contribution. This is worthy of being explored further in a separate blog devoted to it. I’ll do so, quoting from your comment as a starting point.

  3. […] I started to read about Terry Laughlin’s experience with one in training for his upcoming Channel Swim in August, and other TI swimmers and triathletes. I am at that stage in my own TI swimming journey […]

  4. You estimated that the average stroke count for an English Channel swimmer is 60. From what did you base this? From first-hand observations of swimmers training in Dover? From discussions with individuals? If so, what was the age range? Was it an average over the entire distance? Is there any correlation to their English Channel times?

    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).

  5. Steve
    It was just a gut thing, based exclusively on thinking about the more typical Channel swimmers I saw training in Dover harbor last summer. My eyeball estimate of those I saw training in the Harbor during the 11 days I spent doing that myself. I honestly didn’t give much thought to how a record-setting Channel swimmer might go at it. I’m sure they probably maintain a much higher rate, in part because they don’t need to maintain it for nearly as long, when they can make it over in 7 or 8 hours, vs perhaps 14 hours. Speaking personally, I held 60 SPM for a 10-mile Maui Channel crossing but felt more comfortable with a mid-50s rate during a 24-mile Tampa Bay swim.

  6. […] How important is speed to an English Channel Swim « Swim Well and …You estimated that the average stroke count for an English Channel swimmer is 60 . From what did you base this? From first-hand observations … […]

  7. Not stroke count. Stroke Rate – 60 strokes per minute or 1 stroke per second. I estimated from personal marathon-swimming experience and talking with Channel vets. My rate is lower and my stroke longer. Most others have shorter, faster strokes.

  8. Hi Terry,

    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.

    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.

  9. Don – Thanks for your comments. I think the title of your blog says it all. I will follow it with interest and good luck with the challenges you’ve chosen for this year.

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