How much does kicking and pulling help you?

The article this week seeks an answer to something triathletes often wonder about. How much does a flutter kick really matter in your swim? If you just stopped kicking, how much slower can you expect your top speed to go? And for that matter, how much does your arm pull really matter? Are they the same, or different? To get to the bottom of this mystery, your humble author (Duane Dobko) suited up yet again to get some data.

In this experiment, I swam a series of 25 yard sprints. I did 4 sprints flutter kicking (with board), then 4 sprints pulling (with pull buoy), then 4 sprints swimming (kicking and pulling), all as fast as possible. I took full recovery between each sprint. From this data, I could determine how much faster (in %) I get when: I add a pull to a kick, AND a kick to a pull. I could then compare the % gains in speed with kicking and pulling to gains in the use of wetsuits. In previous experiments, I showed that a full sleeve wetsuit makes you about 7.9% faster. The data and results are presented below.

Based on the data, the addition of the pull to an existing kick produced a huge % improvement in times (almost 30%). Although the addition of a kick to an existing pull did not do as much, it improved times by 10%, which is larger than the expected time improvement that a wetsuit provides (7.9%). Thus, if wearing a wetsuit in a race is important to you, then your ability to flutter kick should be important to you as well.

It is true that this experiment would be more accurate with a higher sample size of good swimmers (the sample size is 1). Maybe some people can race well with a kick that makes them less than 10% faster. But the chance of a kick making a negligible contribution is pretty small. Even a kick that makes you just 5% faster is close to the improvement of a wetsuit, and it costs a lot less than a wetsuit!

I hope this article has improved your understanding of the role kicking plays in top swimming times. Having a good kick is so important in a triathlon swim, just because drafting is such an important part of the race. If it weren’t for drafting, all that would matter would be how fast your endurance engine can go over a distance. But triathlon swimming isn’t like that.

In open water swims, there are turn buoys, waves, and groups of people swimming around you in all directions. Any of these and other factors can split competitors up and cause gaps. A person that can instantly make themselves 10% faster by throwing a kick in will have a huge advantage over those who don’t. They can afford to draft off of people with much greater pulling power than them. Then when gaps open up, they can add a kick to either stay in the draft or pass. Having a good kick allows you to get out of potentially dangerous situations fast, such as when a larger competitor is trying to swim over top of you.

Just because you have the ability to go 10% faster in a triathlon swim doesn’t mean you need to always use it. The key is to use your swimming legs in such a way that you can still feel fresh on the bike. Personally, I use a phase approach to kicking and pulling. I spend roughly a minute where I’m really focusing on arm pulling, then about 30 seconds where I don’t pull as hard and kick more, then repeat. The 30 second kick phase is just enough too maintain speed, and allows my arms to rest up a little bit compared to my non-kicking competitors. The net result is that I can swim at a higher intensity for a longer period of time.

I deliberately relax the kick in the last 25 yards into a turn buoy, knowing that a sprint after a turn is the most effective way to get rid of someone drafting off me, or the most effective way to get dropped out of a pack!!! I make a big effort to keep some leg strength for the third quarter of the swim. This is the part of the race where everyone fades, and where a good kick helps the most.

So, what does kicking and pulling mean to you? Pulling is a much more vital component of swimming, but kicking is still relevant. If you are just looking to finish your race, then a good pull is all you need. But if you are interested in seeing how fast you can go, then you need to develop your kicking abilities. A 10% improvement in speed doesn’t make kicking sound like much compared to a 30% speed improvement with pulling. But the 10% you get out of a good kick is bigger than what you can expect to get out of a wetsuit. And a good kick doesn’t cost that much. It just takes some practice!