Full Professor. Physical Education and Sport Department. Faculty of Sport Sciences. University of Granada
English first draft review: Néstor Arellano
Natural sound English review: Bridger Bell [Strive Swim Practice Planning Program]
The World of Swimming has been upended by two incredible performances in 50y and 100y freestyle by Caeleb Dressel. Dressel’s earlier performances teased in this direction and have now realized a collective dream.
This paper will undertake analysis of the first event (50y free) in detail; afterward we will extrapolate from his result a 50m short course schema.
Methods and limitations:
The lanes were used as visual image data references for this analysis, being coloured in blue and white. On both sides of the swimming pool, the two turning areas were coloured blue at 5 yards (4.572m). Two specific 15m marks are included in the lane to limit the submerged distance. Therefore, the 25y pool has a 15y space (13.71m) between the turn areas. This space is marked in the lane by 20.5 groups of four lane buoys (four in white and four in blue). Thus, the space of each four buoys segment is about 0.365y (0.334m). The distance 25y is equivalent to 22.86m; 50m is equivalent to 45.72; and 100y is equivalent to 91.44m. An additional source of error has to be considered when times of the underwater displacements are collected. They are approximate, but our experience on these analyses (from Barcelona-92 Olympic Games) can guarantee a high degree of accuracy.
A proprietary algorithm allowed us to collect each event timecode and to include it – in the specific field of the database – to perform the calculation of the race analysis variables. The official results are included in the analysis and combined with the times collected from the video analysis. Both event times were synchronized thanks to the starting lights located under each starting block.
These events included many unofficial world records as the fastest start or the fastest turn in an official competition. Not only is the race extraordinary; so too are its technical components.
Initial data from the start is included: hands leaving the block [HLB], back leg leaving the back support [KLB] and finally front leg leaving the block (collected from the official results as “reaction time” [RT] and additional validity check as different official times). All these data are included in the Table 1.
Two versions of the results are included: results based on yards references as they were explained in the methods sections and results measured in meters to compare with previous results of international performances in meters. The Table 2 includes these results.
Dressel was almost the last swimmer to touch with the hands the surface of the water [WHT] after the start dive (1.03s), while he arrived to the 5m distance in aproximate 1.33s (and simultaneously with the feet entry into the water, a common race detail in top-level swimmers). He stayed submerged more than half a meter in front of the nearest contender and covered an underwater distance of 12.90m after six dolphin kicks. This advantage was augmented after turning: he covered about 11.20m and performed 6/7 kicks. His undulatory technique was linked with the first two breakout arm strokes using the dolphin kick simultaneously through the first full stroke cycle instead of the flutter kick, similar to M. Phelps breakout technique.
Table 1: Performance results 50y freestyle Caeleb Dressel.
|T 25y + 15m||14.40|
* Provided by the official results.
Table 2: Performance results 50y freestyle Caeleb Dressel adapted to distances measured in meters.
|T 25y – 5m||6.10|
|T 25y + 10m||11.98|
|T 25y + 15m||14.40|
|T 50y – 5m||15.59|
* Provided by the official results.
Table 3: Cyclic variables, emersion distance, number of underwater kicks and number of strokes by lap.
|First Emersion (m)||12.90|
|Emersion T1 (s)||3.97|
|2nd Emersion (m)||11.20|
|Emersion T2 (s)||3.93|
|Underwater Kicks 1||6|
|Underwater Kicks 2||6 or 7|
|Number of strokes 1st lap||8|
|Number of strokes 2nd lap||11|
|Time between the last stroke and the feet touching the wall||0.91|
|Stroke Frequency (cyc/min)1||70|
|Stroke Frequency (cyc/min)2||63|
|Stroke length (m) 1||2.05|
|Stroke length (m) 1||2.24|
|Stroke Index 1||4.91|
|Stroke Index 2||5.32|
+ Extended explanation of all the variables can be found in the references listed at the end.
The results provided in Tables 1, 2 and 3, will allow us to extrapolate a simulated 50m short course performance. The procedure is to add the known times: 15m start time, 5+15m turning time, 5m finishing time, and the distances between them (in the first lap between 15m and 20m; and in the second lap between 40m and 45m) and to assume that the average velocity is similar to the analyzed event (over 5m for a 25m race rather than the 2.86m in the 25y race). This 2.14m of difference per lap are the extra swim distance in the 25m course for both events and constitute the corresponding gap in the calculations that we here extrapolate.
Table 4: Simulated 50m short course Caerel Dressel performance
Table 4 shows the calculated 50m short course time. The application of a swim times calculator converts the 50y 17.63s time to 50m 19.40 short course time, while our prediction based on race analysis data results 19.37 a very narrow difference but includes all the race splits. In this case, the split difference between the first and second lap is 0.76s, while in the 50y event it was 0.67s.
Just a couple of comments about other, previously superlative, performances. At the Barcelona Olympics Games, Alex Popov performed a starting time of 3.33s (10m) (Arellano, Brown, Cappaert & Nelson, 1994); in this case Dressel performed a 2.90s 10m start. A time reduction of 0.43s in the first 10m reflects many changes in this phase: new starting blocks and their corresponding changes in the start technique, new swimsuits, more distance underwater and a likely different approach to training the leg power required in this short distance. More recent results for the 50m short course record by Florent Manadou include a 10m time of ~3s, something similar to the recorded by Dressel, while the time at 15m was 5+s from Manadou and 4.84 from Dressel. The evolution is clear: a higher velocity at the beginning facilitates a better transition to the stroke phase where arm power will be applied at the maximal level. The Manadou Dec, 2014 record, was performed with a 25m time of ~9.7 and a 50m time of 20.26, while the predicted times for Dressel have been calculated as 9.31 and 19.37 – a dramatic improvement.
A detailed analysis allows coaches and swimmers to establish new performance targets and clear training objectives. The race component results can reorient – and offer more detail about – new racing requirements for top-level freestyle male 50m swimmers. This is particularly relevant to the narrow time difference between the first and second lap, opening a nearly negative-split race pace paradigm in this short event
This project DEP 2014-59707-P “SWIM: Specific Water Innovative Measurements applied to the development of International Swimmers in Short Swimming Events (50 and 100m) has been financed by the Spanish Ministery of Economy, Industry and Competitiveness [Spanish Agency of Research] and European Regional Development Fund (ERDF).
Arellano, R., Brown, P., Cappaert, J., & Nelson, R. C. (1994). Analysis of 50-M, 100-M, and 200-M Freestyle Swimmers at the 1992 Olympic Games. Journal of Applied Biomechanics, 10(2), 189-199.
Morais, J. E., Marinho, D. A., Arellano, R., & Barbosa, T. M. (2018). Start and turn performances of elite sprinters at the 2016 European Championships in swimming. Sports Biomechanics, 1-15. doi:10.1080/14763141.2018.1435713