Swimming Strokes and Technique

There are four distinct competitive swimming strokes: backstroke, breaststroke, butterfly, and freestyle. Many descriptions of these swimming strokes will tell you how they should be done, with long-winded descriptions of each phase of the stroke and what needs to be done where. Unfortunately, swimming is not done in a series of distinct actions. Swimming, like the water in which it's performed, is fluid. Any action taken without proper understanding of the fluid nature of water will slow the swimmer down and take far more energy than necessary. Therefore any discussion of where to place one's head, shoulders, hips, or any other part of the body, is moot without a basic understanding of fluid dynamics.

Many years ago now, at one of the better colleges several physicists were eating lunch around a pool where a practice was being held. As they ate their food, one of them happened to notice a strange occurrence. The point at which a swimmer put his hand in the water and began his stroke was actually behind the point in space where he took his hand out at the end of his stroke. This puzzled the physicists intently. Up to that point, it was thought that a swimmer propelled himself through the water by grabbing a piece of water, climbed along it, like a rung on a ladder, then threw it back behind him at the end of the stroke. Due to the less than solid nature of water, it was thought that the hand should exit the water behind its initial starting point, or at best at the same place. The fact that the hand was exiting the stroke ahead of its starting point flew in the face of their supposed action-reaction Newtonian model of how swimming worked. Something else must be at work.

After some months researching the issue, it was found that the swimmers in question were not using water to push themselves forward, but they were utilizing Bernuli's Principle to "lift" themselves forward through the water. When an airplane moves forward, the air moving over the top of its wing moves much faster than the air moving underneath. Slow moving air creates more pressure than air moving quickly so the higher air pressure below the wing causes the plain to experience lift. In a similar way, a swimmers lightly cupped hand creates a hydrofoil shape creating lift in much the same manner.

Now this story may well be apocryphal, but it illustrates well the most important nature of swimming. Everything you do in the sport involves water and how water behaves. Ignore this fact at your peril.

Each swimming stroke, done properly, allows the swimmer to utilize Bernuli's Principle and other aspects of fluid dynamics to work with the water in creating the most efficient and fastest progress through the water that is possible. Most swimmers don't understand these principles directly but they feel the difference when they're doing it right. Competitive swimmers call this difference a, "feel for the water." As we discuss each stroke in more detail, I will try to let you know how a stroke should feel when you're doing it well. Then you'll be closer to finding out what that, "feel for the water," is like.

The Swimmer that Made Bernuli's Principle Apparent, Mark Spitz