Researched, produced, and prepared by Brent S. Rushall, Ph.D., R.Psy.

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This analysis is of the Chinese swimmer Sun Yang. In winning the 1,500 m race at the 2011 World Championships, he set a new world record of 14:34.14. The whole stroke cycle takes 1.7 seconds.

This stroke analysis includes a moving sequence in close to real time, a moving sequence where each frame is displayed for .5 of a second, and still frames.

The following image sequence is close to real time (each frame is approximately .1 seconds apart). It will play through 10 times and then stop. To repeat the sequence, click the browser's "refresh" or "reload" button.

The following image sequence shows each frame for half a second. It will play through 10 times and then stop. To repeat the sequence, click the browser's "refresh" or "reload" button.

At the end of the following narrative, each frame is illustrated in detail in a sequential collage.

Notable Features

Much could be done with streamlining in this swimmer. The head could be pushed lower in the water with possibly the eyes looking directly at the bottom of the pool. That reorientation would cause the hips to rise and the torso to flatten. Both are features of improved streamlining.

Recovering over the water rather than entering as early as demonstrated with both arms would also reduce drag resistance created on and after entry.

Sun Yang swam the majority of the first 1,400 meters of the race with a two-beat kick or a three-beat kick depending on the definition of a kick. Over that distance he was behind record pace. For the last 100 meters he employed a very fast moderate size six-beat kick and blistered home in 54.22 with the last 50 meters in 25.94.

The pitfalls of an overtaking stroke are clearly shown in this swimmer. The inertial lag after the left arm pull is slightly longer than that after the right arm. Approximately six of the sixteen frames in this stroke do not demonstrate propulsion. That equates to ~38% of this stroke not being in propulsion, a state where the swimmer slows. Improvements should be expected if propulsion becomes more dominant and inertial lags are reduced or eliminated. That should result in closer compliance with Newton's First Law and a state where energy expenditure is more efficient.

Overtaking strokes are relatively common in male distance freestylers. The inherent errors of motion and undesirable limitations of that stroking format could be argued as being the principal reason why the men's 1,500 m race has improved the least of all swimming races and strokes over the past decade (even despite the introduction of the performance-enhancing super suits). Grant Hackett's world record set in Fukuoka in 2001 was 14:34.56. In this race, Sun Yang improved that record by .42 seconds. Until overtaking and uneven stroking characteristics are removed from men's distance-freestyle, the record will remain quite stagnant. Given the usual growth characteristics/curves of world records, to which the men's 1,500 m does not comply, the record for this event would seem to be potentially the easiest to break and the amount of improvement should be very substantial.

Sun Yang at 1,225 m

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