By Peter Hendriks
This is a hot topic all over the world and draws a lot of different opinions.
I personally am fascinated by the subject and apply it to my own swimming at all times. As a specialist technique coach who spends his week either videoing, analysing or correcting swimmers, of all levels and technique, it is important to understand the subject.
In order to understand swimming efficiency we first need to understand the KPI’s.
Measurable KPI’s 1. Stroke Length (SL) 2. Stroke Rate (SR) 3. Height 4. Wingspan 5. Foot size 6. Body Weight 7. Frame Size 8 Hand Size 9. Age 10. BMI Harder to Measure KPI’s 1. Perceived Rate of Effort 2. Fitness Level
The formula for measuring all swimmers speed is Velocity = Stroke Length x Stroke Rate or V = SL x SR.
Stroke Length is measured by the number of strokes a swimmer takes per lap after the push off or dive distance is subtracted. ( eg if pool length is 50m, push off is 5m and the number of strokes to swim a lap is 45 , then the swimmer is travelling 1m per stroke).
The time it takes to swim a lap is then determined by how quickly the swimmer can take each stroke, whilst holding Stroke Length.
Here is an example of two totally different elite swimmers (it is assumed both are efficient in their stroke). Swimming side by side in a 1500M race, each one lapping at approx. 60secs per 100M, one taking 39-40 SPL and the other taking 30-31SPL. (Felix Wellbrock v Gregorio Paltrinieri at the Tokyo Olympics). Is it as simple as saying that the person who was taking the least number of strokes per lap was the most efficient? Everyone is assuming that both swimmers were giving it their all, but does that mean that the Effort Rate of each swimmer was the same?
In the end, Wellbrock came in ahead of Paltrinieri on this occasion, however, was that due to a higher level of efficiency or some other variable on the day?
At Swimwell we work on sustainable SL and SR and believe that Swimming Efficiency is not a “one size fits all” measurement.