So, you are swimming faster than before…but do you know why?

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It is not terribly uncommon to see a swimmer’s speed increase year to year as they train.  Everyone hits points where they feel like they aren’t getting any faster and some do stay stagnant for a quite some time and don’t get faster, but in general a good portion of those that train on a regular basis do get a bit faster.  Especially in the first few years of swim training where there is a great deal of improvement to be had.  As form and experience increase, it gets more and more difficult to get faster but some still see minor increases year to year.

The one thing that IS uncommon though is for a swimmer to be able to tell you exactly how they got faster if they do indeed succeed at getting faster.  Do you know what variable in the speed equation you changed to make you faster?  Do you know how you changed it?

I have talked about the simple swim speed equation in other blog posts in the past and Terry Laughlin has talked about it extensively on his blog and on the Total Immersion site but I am going to go right back to it for a minute here.

Swimming Speed = stroke rate (time per stroke) x stroke length (strokes per unit of distance)

For example, if you swim at a stroke rate of 1.00 sec/stroke and take 17 strokes, it will take you 17 seconds.  Add in the distance you covered and you get a swim speed in sec/yd or whatever units you use.

So, basically, we have an equation with three variables.  The equation is not a complex one and it is easy to solve for any of the variables if you know the other two.  The problem is that most swimmers only measure one of the variables and the one they usually choose to measure is speed.  Just about any swimmer measures how long it takes them to complete 50 yds, 100 yds, 200 yds, 500 yds, 1000 yds, 1.2 miles, or whatever the distance is that they are swimming that day or in that interval.  So, they know how fast they swam those distances a month ago and they know how fast they swam them today.  If it was faster today than a month ago then that is considered a win.  Understandable, right?  Sure.

However, from the equation, there are two variables that you can change to affect your speed.  Do you know which one you changed to swim faster today than you did last month?  Did you stroke at a faster rate but at the same stroke length or did you increase your stroke length at the same stroke rate?  Maybe it was some combination of the two.  If you don’t know what changed to make you faster, how do you know what to work on to continue to improve?

These are extremely important questions if you want to improve your swimming in the most efficient way.  For instance, let’s say that all of your training over the last month has been sprint interval sets and it has really taught you how to increase your turnover rate.  Awesome…so now you are stroking faster and swimming faster (not always the case if you lose grip at the same time but let’s assume for now that it is true).  At some point, you won’t be able to continue to stroke faster and faster and see speed improvements…there will be a point when your faster stroke rate will just become an energy wasting churning of the water because the rate is too fast to hold proper form.  This doesn’t mean that you can’t still get faster though.  You can still change the other variable…stroke length.  Having a longer stroke at the same stroke rate makes you a faster swimmer too!  Unfortunately, the purpose of this blog post is not to explain the details of how to train for a longer stroke or a faster stroke…that is a whole different post or maybe a series.

OK, so with all that said, let me see if I can get to the point of this blog post.

Q:  What can you do to make sure you know how/why you got faster (or why you didn’t) in your swim training?



The cheapest and lowest tech way to do this is to simply add stroke counting into your swimming on a regular basis.  If you time your swims (which you are likely already doing) and you take an average stroke count for either one length or one lap of the pool, you have two of the variables in the equation.  A great way to do this is to keep “swim golf” scores during some of your swims.  A swim golf score is the sum of the number of seconds it takes to swim a lap and the number of strokes taken.  For example, my golf score today hovered around 69 (30 total strokes, and 39 seconds in a 50 yd lap).  With this simple game, you can see what happens to your score as you increase or decrease your pace.  If you swim faster and take the same number of strokes as before, your stroke rate went up while stroke length stayed the same.  If your strokes go down, then you increased stroke length and so on.  You can focus on various elements of your stroke while playing swim golf and see how they affect your score and see what improves your swimming the most.

A more high tech and precise way of measuring a second variable is to invest in a Tempo Trainer.  Tempo Trainers can be set at a very wide range of stroke rates (in sec/stroke) and will give you a nice beep for every stroke to keep you on tempo.  With a tempo trainer on, your stroke rate is constant and takes the possibility of increasing or decreasing your stroke rate as you fatigue or lose focus almost completely out of the picture (obviously, you could ignore the beeps if you wanted to).  You can read about my progress from last season with a Tempo Trainer here.

As an example, last year, I swam my half ironman at a tempo of 1.05 sec/stroke on the tempo trainer.  I trained in the pool this way and in 300 yd timed swims before my race, I was swimming 4:20ish at a tempo of 1.05.  Today, I swam a 300 yd timed swim at the end of my workout with the tempo trainer set at 1.05 and finished in 4:07.  From this data, I know that I am now able to cover more distance per stroke at that tempo than I was able to cover last year.  This makes sense because most of my training this year so far has been working on increasing my stroke length with very little high intensity interval work or stroke rate work.  If I had done these timed swims without a tempo trainer or at least counting strokes, I would have no idea if I had increased tempo, increased stroke length, or some of each.  Now, with that data in hand, I can focus on being able to move that same stroke length into a slightly faster tempo using the tempo trainer.  I should see some speed gains there as well.

If you want more info on how to swim with a tempo trainer, there is a ton of info in the “favorite practices and sets” section of the Total Immersion forums or you can contact me via email at

Happy Swimming!


  • lisa

    April 18, 2012

    Ugh…more swim calculus ,;)

    • BASEtraining

      April 19, 2012

      Whatever…you love it.