Triathlon Kick Impact Test

Updated: Oct 5, 2021

Why Kicking Matters to Triathlon

Swimming intensity in triathlon has a direct effect on the athletes sequent bike and run performance. The legs are the obvious main contributors to forward propulsion in cycling and running, but this is not the case in swimming. As outlined by Professor Giorgio Gatta HERE

“Swimming freestyle using your legs only generates a lot of lactic acid (Meyer 1999) and uses up three quarters more oxygen than swimmingly with just your arms (Adrian 1966). So, using your legs is not very advantageous and very energy-consuming. It also seems to be hard to train your legs: Konstantaki (2007) has worked out that, among swimmers training the same way, those devoting 20% of training specifically to just their legs had no “statistically significant” performance gains over 400m freestyle.”

With only 15% of forward propulsion being generated by the legs in swimming, and potentially less with a wetsuit/swimskin, triathletes need a way to measure the impact of their kick on their triathlon performance. If a triathlete is kicking too much, their relative swimming intensity will be elevated, and their legs will be more fatigued for the subsequent bike and run segments.

The Test

A simple test to measure if an athlete is kicking too much is to test for speed and blood lactate levels after swimming with and without kicking over a specific distance. The distance needs to be long enough to ensure that you can differentiate between intensities, and long enough to be representative of the actual race. For example, swimming 100m with and without kick won’t show much difference as compared to 800m, nor would 100m relate very well to swimming 1500m or 3800m open water.

The following protocol was design to address these issues.



Approx. 1km @ a easy-moderate intensity

Main test set

4 x 600m @ perceived race intensity with full recoveries (minimum 5 min).

  1. Swim

  2. Pull Buoy

  3. Focus on a reduced kick, ideally 2-beat

  4. Swim

Measurements: Lactate immediately before and after, time to complete 600m, swim metrics from watch if possible.


Easy swimming or continue with the usual swim workout.

Analysing the Results

A comparison of the result should indicate how kicking is impacting the athletes swimming intensity.