The starts and the turn techniques employed in a swim race are the subject of intense practice by all competitive swimmers. Starts and turns are movements that are distinct from both the strokes used by a swimmer and from one another.
The start has three components, each of which can be broken down for discrete analysis—the starting block, the dive, and the pullout (breakout). All swim events, except the backstroke, begin on the elevated starting block situated at the edge of the pool. The backstroke commences with all swimmers in the water, facing the edge of the pool, grasping handles that permit a push off into the lane. To achieve maximum speed from the start block, the swimmers seek to keep their center of gravity as close to the edge of the block as possible. At the sound of the start, the swimmers employ a combination of explosive leg drive and a push with the toes from the surface of the block.
The dive is intended to be one that creates as little water resistance on entry as possible. The swimmer, depending upon the stroke to be employed during the race, will endeavor to take an angle of entry that balances speed through the water and an ability to seamlessly begin the stroke cadence. The transition between the dive and the stroke itself is the pullout, where the swimmer moves dynamically to the racing position in the water.
There are two general classifications of turns: the open turn and the flip turn, or tumble turn. The use of a particular type of turn, and the accompanying period of time in which the swimmer may remain underwater (in a desirable hydrodynamic position) after the completion of the turn, are specified in the rules of the sport as determined by FINA.
The flip turn is an important component of freestyle swimming. The turn is intended to permit a coordinated change of direction that allows the swimmers to maintain both their speed and the cadence of their stroke. A flip turn begins with a somersault, with the swimmers bringing their arms forward to create a long, slender upper body profile. As the upper body is being extended, the swimmers use the wall of the pool to push as powerfully as possible. In this position, the swimmers will often remain under the surface, propelling themselves with an efficient dolphin kick (legs together, moving in the manner of a dolphin). The distance in which the swimmers are permitted to remain underwater after a flip turn is also regulated in each swimming discipline.
The open turn is also used to preserve speed and form. In an open turn, the swimmers seek to coordinate their approach to the wall and the stroke rhythm; the swimmers use one hand to effect a push off from the wall, while bringing their feet and legs into a tuck position. The swimmers push off from the wall, with the entire body under the surface, extending from the tuck into a streamlined body position, from which they resume their stroke.