For better triathlon swimming, a strong swim kick can give you powerful propulsion through the water, but for some of us there may be a smarter way to swim, says Triathlon Plus and coaching editor Phil Mosley.

Smart kicking improves body position and helps to maintain speed

Let’s not beat around the bush – most triathletes are poor at kicking. Sadly I include myself in this frank assessment. Give us a kick float and we’ll churn our legs frantically, travelling nowhere fast. Swap the kick float for a pull buoy though, and it’s a different story. Most triathletes are great with a pull buoy because it means they don’t need to use their legs at all. They can just leave them floating behind them while they get on with the real business of swimming hard.

I’ve seen some triathletes who actually travel backwards when they use a kick float. This is often because their ankles are stiff and because they bend their knees far too much. The kicking motion should come from the hips, not the knees. Competitive swimmers are usually better at kicking than triathletes, and many of them can kick faster than we can swim full stroke.

Thankfully, as triathletes, we often race in wetsuits, so we don’t need to be such fantastic kickers. After all, wetsuits have 5mm of neoprene to help our legs float. In fact, as triathletes, you may wonder why we need to worry about kicking at all?

Research carried out on swimmers in the 1980s showed that, on average, kicking gives 10% more speed compared to swimming with a pull buoy. Other studies have shown that some athletes can gain up to a whopping 27% from kicking, while some others actually slow down by up to 6%. So, for most swimmers, it seems that kicking is a valuable speed booster.


Speed isn’t everything though. While kicking may make you faster, it’ll wear you out quicker. Studies looking at the oxygen consumption of competitive swimmers showed that they used nearly four times more oxygen when kicking only, compared to when pulling only. These reports are supported by several other studies that all show kicking causes a big increase in the energy cost of swimming. So, while kicking may speed you up slightly, it’s often outweighed by the fatigue it causes.

As a result, many coaches believe that triathletes should minimise their kick during a race, in order to conserve energy. So unless you’re a brilliant kicker, you should only do the minimum required to support and stabilise your stroke. The only time you might kick harder would be at the race start (to get clear of other swimmers), approaching a turn buoy (to get the best line), or to speed up to someone’s toes (to get a free draft).

It’s still important to practise your kick in training, even if you don’t use it so much during a race. A good kick will help you stay level in the water, which will help the rest of your stroke. It’ll also make you more efficient whenever you do have to start kicking in a race, leaving you with more energy for cycling and running afterwards.

This article was originally published in Triathlon Plus magazine – click here to subscribe

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