Underwater Kicking: Some Numbers

UW kick

These days everybody knows about that underwater kicking is a fast and necessary aspect of swimming. And we all know that the fastest swimmers generally have incredible underwater kick speeds and distances. But what surprises me over and over is the general lack of numbers involved with this knowledge.

How fast is it? How long can top underwater speeds be maintained. What’s the optimal breakout point? What’s the speed difference between underwater kicking and swimming.

I’ve done some tests on my own swimmers, viewed a ridiculous number of videos, and have done some research to try to come up with some of these answers. So far, just for backstroke.

Underwater Speeds

The key to underwater kicking is that the swimmer is not generating speed, but merely trying to maintain speed. This is an important distinction, as it affects how the body should move. (For more on this, see the second half of my post, More Than You Want to Know About Underwater Kicking).

There are two other things to keep in mind with underwater kicking:

  • underwater kicking at its fastest is slightly faster than freestyle swimming
  • underwater kicking speed cannot be maintained for long

Put these two things together and we can start to understand the underwater strategy of elite swimmers. Ideally, you want to breakout of the underwater phase when the underwater kick speed slows down to swimming speed, or 15 metres, whichever comes first. There is no advantage in staying under if you’re kicking slower than you can swim. However, speed, fatigue and a need for oxygen all pay a role in the underwater phase. We’ll try to find out how much of a role they play.

First, how fast is underwater kicking?

Here are the results for average speed to 15m for the fastest underwater swimmers in the first length of the 100 backstroke at the …read more

Source: Rick’s Blog