A gift for those of you who would love to geek out a little bit more with summer reading and swim math.....
By
USMS.org website
Conventional wisdom tells us that faster freestyle turnover equals faster speed. If only it were that easy! This might be true for our terrestrial counterparts, runners, but water is about 800 times denser than air. That added resistance means the rules don't apply in the same way for both runners and swimmers. Additionally, turnover rate and speed don't share a linear correlation; errors in stroke mechanics introduce drag, and as speed increases, this drag coefficient increases exponentially. Finding the right turnover is personal and based on a swimmer's height (or wingspan), skill level, tempo (rate of turnover), and stroke length. Tempo is measured in strokes per minute or seconds per stroke. For example, 60 SPM is equivalent to one second for each arm stroke. Stroke length is the distance the body moves forward on every stroke. As many short swimmers already know, height is an advantage in swimming. Taller swimmers naturally have a longer stroke length. But shorter swimmers might be able to overcome some disparity if they access the legs effectively. This is why counting kicks per length is important to finding whether more (or fewer) kicks increase stroke length and speed or just burn up more energy than necessary. More often than not, swimmers stroke at tempos that are too fast-beyond their current skill levels-and are forced to kick too much so they can remain stable. These swimmers might be physically able to spin their arms at 70 or 80 SPM, but they don't get the return in speed they should given their stroke rate and added kicks. In addition, that higher stroke rate typically deteriorates in mid- to long-distance swims or toward the end of a main set at practice. The swimmer attempts to swim more yards to build endurance and manage fatigue rather than improving technique and skill to get the most out of each stroke and avoid fatigue. Basically, they're swimming harder instead of swimming smarter. Getting accurate measurements for tempo, stroke length, and pace can be a challenge, especially in 25-yard pools, but you can help your swimmers accomplish this with some planning and a little math. Let's start with measuring tempo.
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