Butterfly: Fastest Yet Most Difficult Swimming Stroke

There are at least sixteen different strokes used in swimming, and about half of these are used in competitions. By simple definition, a swimming stroke refers to a technique used by a swimmer to drive himself forward; the technique involves the coordinated movements of the arms and legs.

Of the different swimming styles that are regulated by the International Swimming Federation (FINA), the butterfly swimming stroke is regarded as the fastest (actually, another swimming stroke - called forward crawl - is considered the fastest, except that it is not regulated by FINA).

A distinguishing feature of the butterfly swimming stroke is the synchronous pull-push motion of both arms. Because of this, its maximum speed is deemed even faster than the forward crawl's; overall, however, it is slightly slower when the recovery phase is considered, during which the speed considerably goes down.

Here's how the butterfly stroke compares with two other FINA-regulated swimming styles in terms of their respective top speeds:

• butterfly - 2.18 meters per second

• backstroke - 2.04 meters per second

• breaststroke - 1.84 meters per second

Another point of comparison between the butterfly and the other swimming styles is the degree of difficulty at which each is performed. For example, the backstroke and breaststroke styles can be performed with relative ease even with an imperfect technique. But the same can't be said of the butterfly, which requires flawless technique.

Beginners swear that butterfly is very difficult to learn, and expert swimmers and swimming coaches agree it's the most difficult swimming stroke indeed. The style involves swimming on the breast while pulling and pushing both arms at "exactly" the same time. Note the emphasis on the word exactly; the technique is considered poor if the arms are not moving perfectly in unison.

Swimmers are unanimous in saying that the difficulty in the butterfly style lies in the recovery phase, when all the necessary over-water moves have to be done synchronously. This means that in that single motion, the swimmer has to take a quick breath while simultaneously lifting out of the water fully his head, arms, shoulders, and part of his chest.

A flawed technique won't be overcome by the swimmer's purely physical strength. Also during competition, the butterfly swimmer is not allowed to swim underwater, except for the first stroke after the start (in which the swimmer is allowed up to 15 meters of swimming underwater before his head breaks the surface) and after each turn.

Another distinguishing feature of the stroke is the kick that accompanies it - the dolphin kick. Here, the legs also move in unison, using an entirely different set of muscles: a forceful up and down kick brings the shoulders above the surface, while the reverse of this kick sequence brings the shoulders back below the surface.

Although the butterfly swimming stroke is known to have been used in a competition for the first time in 1933, the dolphin kick was only developed two years later. The combined windmill-like movement of the arms and the fishtail-like kicks are the keys to the development of this very fast, albeit quite difficult, swimming style.