Swimming is considered one of the most technical sports, and when it comes to swimming faster, it’s helpful to understand the variables that factor into your speed and efficiency.

And the Swimming Equation does just that! If you’re a major data nerd, you’re going to love this…

And if you’re not? Don’t worry, this isn’t complicated algebra, but it will help you make sense of just how much seemingly small things, like turns or underwaters, impact your overall performance.

Breaking Down the Swimming Equation

The swimming equation is written as follows:

ST = S + (UT + TT) + (CC*SR)

  • ST: Swimming Time, in seconds
  • S: Start (Reaction Time + Airtime), in seconds
  • UT: Underwater Time, or how long you spend underwater after the start or turn
  • TT: Turn Time, or the length of time between when you touch to when you push off again, in seconds
  • CC: Cycle Count, or the number of strokes you take
  • SR: Stroke Rate, or the number of seconds it takes you to take one stroke

This equation represents two components: underwater time and overwater time. Underwater time is made up of Underwater Time plus Turn Time. The Overwater time is a function of Cycle Count multiplied by Stroke Rate. The unit for Stroke Rate is in seconds/stroke.

Example: 100m Breaststroke Long Course

Let’s look at the 100 breaststroke in a 50m pool as an example:

Your Start is a combination of your reaction time (how fast you move off the block once the buzzer goes off) and your airtime (how long you’re in the air from when your feet leave the block and when you hit the water). For this example, let’s say your reaction time is 0.7 seconds, and airtime is 0.8 seconds, for a total Start time of 0.8 seconds

Underwater Time is a function of how long your pullouts are. For simplicity, let’s say you spend three seconds underwater off the dive on the first pullout, and three seconds underwater off the dive for the second pullout off the turn. Your total underwater time would be six seconds.

Turn Time is time spent on the wall where you’re not making any forward progress. It’s the time from when you touch the wall to when your feet leave the wall. Let’s say this takes 0.7 seconds. Add that to the underwater time from your pullouts, and we get 6.7 seconds.

Cycle Count represents the number of strokes you take during the race. For this example, you took 40 total strokes: 18 on the first 50m, then 22 on the second 50m.

At a Stroke Rate of 1.25 seconds/stroke, the total overwater swimming time is 48 seconds (40*1.2).

Plugging these numbers into our equation:

0.8 + (6 + 0.7) + (40*1.2) = 56.2 seconds Swimming Time

Your total swimming time for this race is 56.2 seconds.

Using the Swimming Equation to Swim Faster

When you understand the Swimming Equation, you can tweak different variables to determine how fast you’ll swim. While you can definitely shave off a few hundredths of a second on your Start, Underwater Time and Turn Time by improving your dives, your streamline and dolphin kick, and your turns, we recommend focusing more on the overwater aspects of the equation to see the best results.

Related: How to Improve Distance Per Stroke

Try these three options to swim faster:

  1. Reduce Cycle Count: In other words, take fewer strokes and maximize distance per stroke. The key is maintain stroke rate while doing this (spoiler, it’s very difficult!).
  2. Increase Stroke Rate: Swim with a faster tempo. Try to take the same amount of strokes per length, and move your arms faster. You may end up taking more strokes per length, which will increase your Cycle Count.
  3. Do Both: Find balance between the two! Reduce your Cycle Count and increase your Stroke Rate. This is the toughest option, but it yields the best results.

Decreasing Cycle Count is by far the easiest and will deliver the highest return on investment. You’ll improve your efficiency, decreasing resistance in the water and maximizing your distance per stroke.

Increasing your tempo while maintaining Cycle Count requires an increase in propulsion (in short, you need to get stronger so you can pull more water!). Increasing propulsion is much harder, and only comes with seasonal training both in and out of the pool.

Applying the Swimming Equation to Your Training

To swim faster, you need to put in the work during training. Here’s how to shave extra time off of each variable in the Swimming Equation:

  • Focus on Maximum Distance Per Stroke: Efficiency is the name of the game! Train your body to swim with your max. DPS so you can focus on reducing your Stroke Rate.
  • Think About Cycle Count & Stroke Rate When You Fatigue: The real work begins when you get tired. Focus on maintaining your tempo and technique when you begin to fatigue to really train your body to perform optimally.
  • Carry Momentum Off the Walls: Use each turn as an opportunity to go faster off the walls. You might spend the same amount of time underwater, but you can go further.
  • Incorporate SWOLF Sets: SWOLF is “swimming golf,” and is a measure of your overall swimming efficiency. Similar to golf, you’ll focus in reducing your total number. SWOLF = Stroke Count + Lap Split. Download the MySwimPro app for automatic SWOLF calculations when you swim with a smartwatch!

Related: What is SWOLF Score?

Try This SWOLF Swim Workout

  • Distance: 2,000 meters
  • Duration: 45 minutes


  • 1 x 200 Freestyle
  • 4 x 50 Kick Streamline on Back
  • 4 x 25 Drill, FLOW (with Fins & Snorkel)


  • 4 x 50 Drill, 3 Strokes + 6 Kicks
  • 4 x 50 Drill, Bow & Arrow (with Snorkel, Fins & Paddles)

Main Set

  • 6 x 100 Freestyle, Short Rest (with Paddles)
  • 6 x 50 Freestyle Negative Split Stroke Count*

*Count your strokes on the first 25, and try to take 1 less stroke on the second 25

Cool Down

1 x 200 Freestyle Silent Swimming

In summary, swimming can be very complicated, but if you break it up in to these fundamental components, like underwater time and overwater time, it can be much similar to understand. You’ll find ways to improve your swimming that you never thought were possible!

Stay focused on improving the details and you’ll be swimming faster than ever before.



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