Watching the prelim race between Jeanette Ottesen and Kelsi Worrell, it hit me how incredibly alike these girls swim. Yes, I know, they are both obviously, world class sprint fliers so how different can they swim? When breaking it down, you’ll see that they have almost identical stroke length, stroke rate, and head position. It’s a little uncanny.
Here is how Worrell beat Ottesen, or how Ottesen lost to Worrell in the prelims, however you wish to see it.
Their reaction times off the blocks are nearly identical.
Ottesen (.63) vs. Worrell (.62)
Reaction time is a little over-rated. It’s more about the velocity into the water (entry point) and how a swimmer transitions that speed throughout their breakouts. Notice how Worrell’s arms go further back than Ottesen’s on the initial push, as well as her head is snapped higher. Ottesen is the first to hit the water.
Ryan Atkison, a biomechanist, shared the science behind the start.
“Our main finding was that swim start time is predominantly related to water time and determined to a lesser extent by block time and flight time. We conclude that more emphasis should be given to the water immersion behaviour and the gliding phase when analysing swim start performance. Furthermore, significant differences were found between the grab start and track techniques as regards the biomechanical parameters representing the take-off phase and water phase.”
Here’s a link to read the abstract: https://www.ncbi.nlm.nih.gov/m/pubmed/27239685/
1st Underwaters and Breakout
Worrell is undoubtedly the better sub kicker, but because of the higher force of Ottesen’s dive, she manages to stay ahead.
It is not until the breakout where the race changes. Ottesen stays under 1-2 kicks too long and destroys her momentum. Worrell, on the other hand, transitions perfectly from kicking into swimming and easily catches up with her. She’s already entering into her 2nd stroke before Ottesen has taken her first.
The Turn and 2nd Underwaters
They go stroke for stroke into the turn and they push off at the same time.
Worrell, in classic American style, pushes off a little deeper. She uses her lethal sub kicks to go further and breaks out with incredible speed. Ottesen’s breakout is light years better than her first but she comes out half of a body length behind.
They then go stroke for stroke for 7 strokes. Worrell finishes at maximum velocity with picture perfect length. Ottesen, being a few tenths behind, does not catch her finish perfectly but thanks to her momentum, was not awful.
The focus of this race breakdown is that it’s all in the details. Every tenth of a second counts.
Worrell broke the American Record in this prelims swim with a 24.94. But, in the finale, Ottesen put together her perfect race to come up victorious.
And, in fact, Ottesen ended up being .02 quicker than Worrell’s American Record prelims time.