Editor’s note: Swimming World is posting the following article by permission from Swimming Science in light of the recent discussion regarding Ryan Lochte’s underwater kicking technique for freestyle.
Analysis by Tiago Barbosa
I decided to compare Ryan Lochte’s dolphin kick power in the men’s 200 free event in the prone (front) and back positions at Kazan 2015 and London 2012. As you may have noticed, he changed slightly the turning technique, performing the underwater dolphin kick on his back in freestyle races. Check the video of his race last June at the Speedo Sectionals in Athens, Georgia.
There is a mathematical model to compute the kicking power. The model was originally developed for fish and eventually it was adapted to humans. Amid the excitement of Lotche’s performances and all the talk about the new technique, I have decided to compare his kicking power. This will measure the power of one kick in three separate instances, as opposed to the average power generated in the entire underwater portion:
- On the first turn in the 200 free heats at Kazan 2015, he did 3 kicks – one on his back, another on his side and a third one on his stomach. I selected the single kick he did on his back for measuring.
- For the third turn in the 200 free heats at Kazan 2015, he did eight kicks in the back position, one in the lateral position and the last one in the prone position, before resuming the swim stroke. I am measuring one of the kicks on his back.
- The third turn in the 200 free semis at London 2012 features one kick in the lateral position plus five in the prone position. I will measure one of the five kicks in the prone position.
In his new technique of kicking on his back, he delivers a power of 84.65W, while in the prone position it ranged between 47.29W (during the first turn of the heats at Kazan 2015) and 69.18W (semis at London 2012) (see table below).
It seems more or less obvious that one expects higher power outputs during the semis than the heats of a major competition. The surprise, though, is that with the new underwater technique he reached a higher power output during the Kazan’s heats than at the Olympic Games. I am wondering if he was “testing” the technique to check if should use it later on at the semis and the final. Or maybe things were getting too tight; he was drifting behind and thought “I better turn on the turbo to catch these guys.”
Having said that, please do not rush to the swimming pool and immediately start performing underwater dolphin kicks in the back position. Pace yourself, because there are some things that we must acknowledge. First, Lochte is an elite underwater kicker ,and few in the World that can rival him. Second, we shared the findings only for three kicks. We need more evidence and some comprehensive research on this to clearly advise one to change the turning technique (unless that one is Lochte). However, we do know that when gliding in the lateral or back position, the drag force is lower than the prone position (Marinho et al, 2011).
Last but not least: Consider that the turn depends on several other factors that I did not consider today, such as the depth and efficiency of the kick. It is clear, however, that Ryan Lochte is faster kicking on his back than any other position.
Marinho, D., Barbosa, T.M., Rouboa, A., & Silva, A. (2011). The hydrodynamic study of the swimming gliding: a two-dimensional computational fluid dynamics (CFD) analysis. Journal of human kinetics, 29, 49-57
Tiago M. Barbosa is a Ph.D. degree recipient in Sport Sciences, and a faculty member at the Nanyang Technological University in Singapore.