This video does not teach you everything you need to know about streamlines. It does not teach you whether it’s faster for you to dolphin kick on your front, back, or side. It doesn’t tell you with which part of your body you should initiate your underwater dolphin kick.
But, if you have trouble communicating to your swimmers the value of a streamline, this video is all you need.
Michael Guerra is a fixed-gear cyclist, who, while originally staging his superman downhill technique for an ad, has demonstrated the value of body position in reducing air resistance as, without his feet on the pedals, he blows by his competitors by simply using gravity and having a superior body line.
This is incredibly unsafe, but fortunately and shouldn’t be tried on a bike by anybody who is not a trained professional, but it can be a valuable lesson for swimmers in water, where the landing is significantly softer.