Comprehending this simple equation could bring you a new level of understanding in the pool.

Comprehending this simple equation could bring you a new level of understanding in the pool.

When I wrote Swim Speed Secrets in 2011, I had one principal goal: to steer swimmers and triathletes away from excessive gliding. There was then so much talk of low stroke count that athletes were led to believe this factor was the one and only key to fast swimming. But stroke count is only half the equation that determines your swimming speed!

In this post, you will be presented with the big-picture view of swimming. Once you understand the big picture, the details of swimming technique will begin to make much more sense. You will be able to answer many of the questions about swimming technique for yourself, and your swimming will go to a whole new level. You will have confidence, and the laps up and down the pool will begin to mean something. The best part is how simple it all is.

What is swim stroke count?

First, let’s set the stage: You are going to push off the wall and swim 25 meters. We will assume that you begin the 25-meter swim with a good underwater streamline—a contoured body position used by swimmers to reduce water resistance after diving into a pool or pushing off a wall. The vast majority of elite competitive swimmers employ an underwater streamline for 2–3 seconds before surfacing to begin stroking.


Now you are on the surface swimming.

Only two things affect the time it takes you to get from your breakout (the moment a swimmer surfaces and begins stroking) to the end of the pool:

1. The number of strokes you take to get across the pool
2. The rate at which you take those strokes (turnover)

Number of Strokes and Rate

One stroke is a full arm cycle. In other words, one stroke is from the point when one arm enters the water until that same arm enters the water again. A different way to count strokes is to count “one” when the right arm goes in and then “two” when the left arm goes in, and so on. Both methods of counting are equally acceptable, but in this case stroke counts refer to full cycles.

Let’s say that it takes you 10 strokes (full arm cycles) to get to the end of the pool. Let’s also say it takes you 1 second per stroke.

If you multiply the number of strokes by the rate at which you take those strokes, then you get your time.

Here is what it looks like in equation form:

(Number of Strokes) × (Rate of Turnover) = Time (in seconds)

Let’s insert the numbers from our example:

10 strokes × 1 second/stroke = 10 seconds

That’s it. There is the big picture. You can only get faster in swimming in one of two ways:

You just learned what I learned at age 25. I had competed in two Olympic Trials (1988 and 1992) before I learned this simple equation. A new level of understanding opened up for me, and this knowledge helped me make my first Olympic team in 1996. You might be tempted to take just this one thing and run with it (and you could), but while it is true that only two factors affect our swimming time, many things affect those two factors. Still, we are on our way. We now have the big picture around which we can frame the details of technique. So remember, when you read something about swim technique, or if your coach tells you to change your stroke, ask yourself how it will influence either the number of strokes you take or the rate at which you take them.