The Basics of Olympic Swimming Rules

US Olympic swimmer Michael Phelps in competition
Al Bello / Getty Images

At the international and Olympic level, swimming is governed by FINA (Federation Internationale de Natation). They also govern water polo, diving, synchronized swimming, and masters swimming. The complete set of swimming rules for all aspects of the competition are available on the FINA website. Any country that has a swimming program and swim meets to move swimmers onto the international stage set that country's swimming rules based on the FINA rules.

Olympic swimming uses four basic swimming styles or strokes. Freestyle, backstroke, breaststroke, and butterfly (or all four within one race—that is called the IM or individual medley).

There are 16 swimming pool events for men and women swimmers in the modern Olympic Games. In 2008 an open water, 10-kilometer marathon swimming race was added to the Olympic Swimming program.

Freestyle or Front Crawl

Freestyle is not specifically defined the way other strokes are—it is generally though of as front crawl, but any style could be used, including those not considered as competitive strokes. For competitive swimming purposes, everyone thinks of freestyle as the front crawl.

  • Freestyle is the fastest way to move from one end of the pool to the other (not counting underwater with kicking) and everyone in a freestyle race in the Olympics will use front crawl.
  • In the individual medley and medley relay events, the freestyle portion must be done with a style that has not been used already—no backstroke, breaststroke, or butterfly.
  • Freestyle swimmers use an alternating arm action, an alternating leg action, and breath to the side.
  • Freestyle swimmers use a forward start off of a starting block. They might do a few dolphin kicks or fish-kicks off the start before they surface and begin to swim.
  • Freestylers do a flip turn at each wall. They might do a few dolphin kicks or fish-kicks off of each wall before they surface and begin to swim.
  • Freestylers finish the race by touching the wall with some part of their body, usually one hand.
  • During a freestyle swim, the swimmer's head must break the surface of the water at or before 15-meters from the start and from each turn.

Backstroke or Back Crawl

Backstroke swimmers must be "belly-up" whenever they are swimming, with one exception (on their way into a turn). This is measured by comparing the relative position of each of the swimmer's shoulders.

  • The swimmers must have an alternating arm action (and will have an alternating leg action - that is the fastest way to swim backstroke).
  • Backstroke almost looks like upside-down freestyle.
  • Since a backstroker's face is out of the water most of the time, breathing is easier. Most will use a breathing pattern of in on one arm pull, out on the other, or in and out on each pull. Because of this greater ease of breathing, backstroke races are often "even-split"—the time it takes to do each length is about the same for an Olympic-level swimmers. If they are doing a 200 meter race, it might take 30-seconds for the first 50 meters (faster because of the start), then it might take 32-seconds for each of following 50 meter portions. They would split the race 30-32-32-32.
  • Backstroke swimmers start in the water, with their feet against the wall, hands holding on to a starting grip. The swimmers must be rotated towards "belly-up" when their feet leave the wall, but they might be a little twisted, not 100% "belly-up" until they start their arms.
  • Backstrokers do a flip turn at each wall, and do a few dolphin kicks or fish-kicks off the start or off each wall before they surface and begin to swim. The only time backstrokers are allowed to be "belly-down" is as they approach a turn. As part of the turning movement the swimmers rotates from "belly-up" to "belly-down" and then do a flip turn (just like a freestyle flip turn), pushing off the wall on their backs ("belly-up").
  • Backstrokers must finish "belly-up" by touching the wall with some part of their body, usually one hand.
  • During a backstroke swim, the head must break the surface of the water at or before 15-meters from the start and from each turn wall.

Breaststroke or Breast Stroke

The breaststroke is the slowest stroke.

  • Swimmers are "belly-down" and use a simultaneous arm pull, with the arms pressing out (a "Y" shape), then sweeping in, with the hands meeting under the face then extending forward. The elbows must be underwater during the pull and the hands are not allowed to pull past the waist/hips (with one exception on pullouts).
    • A pullout is a "giant" pull, ending with the arms against the sides.
    • Then the swimmer moves the arms to a forward position and does one breaststroke kick.
    • A swimmer is allowed one dolphin kick off of the start and the turn before the end of the "giant pull" of the pullout.
    • Then regular breaststroke swimming begins, including the head breaking the surface of the water during each stroke cycle (1 pull + 1 kick = 1 cycle).
  • The kick resembles a frog kick, but it is not exactly the same. The legs should not break the surface of the water.
  • The breaststroke requires that the left and right half of a swimmer do the same thing at the same time—if one arm is pulling, then the other arm is pulling; they must mirror each other.
  • The head must break the surface of the water once each stroke cycle.
  • Breaststrokers use a forward start from starting blocks and are allowed to do one breaststroke pull-out before they begin actually swimming.
  • Breaststrokers do open turns. They touch the wall with both hands simultaneously, then rotate and push off of the wall. The swimmer must be "belly-down" when their feet leave the wall. They may do one pullout off of the wall.
  • There is no distance limit on how far breaststrokers may go underwater, but they may only do one pullout before they begin to swim regular breaststroke, to include the head breaking the surface of the water.
  • Breaststrokers finish the race by touching the wall with both hands simultaneously, just as they would for a turn.

Butterfly

Butterfly grew out of breaststroke in the 50's and 60's, finally becoming its own separate event at the 1956 Olympics.

  • Swimmers are "belly-down" and must use a simultaneous arm pull, sort of like doing the front crawl pull with both arms at the same time; the arms are recovered over the surface of the water.
  • The kick is a butterfly kick; sort of like a freestyle kick but with both legs doing the same action at the same time. The legs must stay in the same horizontal plane relative to each other. They may not change their relative position to each other. Most butterflyers will have their legs lined up parallel to each other, as close together as possible, trying to create a big fin with their legs and feet (toes pointed in or pigeon-toed). They cannot do a breaststroke kick.
  • Most butterfly swimmers breath forward, but a few flyers breath to the side, like a freestyle breath.
  • Butterflyers use a forward start off of the starting block. They do a few dolphin kicks or fish-kicks off the start before they surface.
  • Butterflyers do an open turn. They touch the wall with both hands simultaneously, then rotate and push off of the wall. The swimmers must be rotated towards "belly-down" when their feet leave the wall, but they might be a little twisted, not 100% "belly-down" until they start their arms. They do a few dolphin kicks or fish-kicks off the turn before they surface.
  • During butterfly, the swimmer's head must break the surface at or before 15-meters from the start and from each turn.
  • Butterfly swimmers finish by touching the wall with both hands simultaneously, just as they would as if they were going to do a turn.

Individual Medley (IM)

The IM race uses all four strokes, in order, butterfly, backstroke, breaststroke, and freestyle.

  • Within each one of those portions of the race the swimmer must follow the rules for that stroke.
  • Before switching from one stroke to another, the swimmer must touch the wall in the same way they would as if it was the end of the race for the stroke they are using as they approach the wall.
  • IM races often feature lead changes as different swimmers are better at one style than others, and they might fall behind or move ahead depending upon what stroke they are swimming.

Relays

There are two types of relays, freestyle and medley. The strokes used in the relays must follow the same rules as used for individual races.

  • Freestyle relays follow the rules of a freestyle race—any style may be used, but the swimmers will all be using front crawl.
  • The medley relay has each swimmer performing one of each of the swimming styles, in order, backstroke, breaststroke, butterfly, and freestyle. The freestyle swimmer is not allowed to use any of the strokes already used, but the swimmer wouldn't they will always use front crawl.
  • Relays begin the same way as individual races, with the swimmer on the starting block (freestyle) or in the water holding the hand grips (backstroke swimmer in the medley relay). The subsequent swimmers all start from the starting block and may be moving or use a "rolling" start. As long as some portion of the swimmer is contacting the starting block when the swimmer finishing touches the wall, the start is legal. This used to be judged visually, but now the automatic timing system normally fills this role, with a tolerance of .04 seconds.

Equipment

Swimming Pool 

The Olympic pool is fast by design, trying to give swimmers the best opportunity for a record-breaking performance.

  • The race course of an Olympic swimming pools is 50-meters long, at least 25-meters wide and is at least 2-meters (over 6 feet) deep (sometimes deeper, as "deeper = faster" because waves won't bounce off the bottom and interfere with the swimmer). The pool has at least 8, 2.5-meter wide swimming lanes. Besides the pool's depth, the pool's lane ropes (also called lane lines, the thick "ropes" between each lane), the gutters, walls, and circulation system are all designed to minimize waves and turbulence.
  • The pool has starting blocks at each end. These are elevated starting platforms used by freestyle, breaststroke, and butterfly swimmers. The blocks also have handles near the water for backstroke swimmers to use for their starts.
  • The pools have an automatic timing system started when the electronic signal is initiated (the swimmers here a beep) and stopped when the swimmer touches the end wall "touch pad" in their lane. This system also allows for mid-race times to be easily seen.
  • To keep backstroke swimmers from crashing into the wall on their turns and finishes, a string of flags is suspended above the pool 5-meters from the end of the pool. The lane ropes also change color at the 5-meter mark.

Swim Wear

  • Swimmers wear suits (closely regulated by FINA—suits must be pre-approved months before the Olympic games) and goggles. Most swimmers also wear swim caps. All of these are designed to help the swimmer, with the idea of minimizing drag kept at the forefront.
  • At the Olympic games, some people think that the fastest swimmers are usually wearing the fastest suits, too. At least that is what the suit's manufacturer wants everyone to think!

Awards: Gold, Silver and Bronze

Only two swimmers per country are allowed to compete in any individual swimming event. Some countries might not have any entries in some events or might have only one entry, all based on how many of their swimmers achieved Olympic qualifying times. Each country that qualifies a relay is allowed to enter one relay team; the swimmers on that relay team might change between the preliminary heats and the finals.

  • Each Olympic swimming heat has a maximum of eight swimmers, but there can be multiple heats for any event.
  • There are preliminaries in the 50m, 100m and 200m distances, followed by the top 16 moving to two semi-final heats, with the winner of each semi-final plus the next 6 fastest swimmers moving to the finals.
  • In the relays and longer individual events the eight fastest finishers in the preliminary heats move straight to the finals.
  • In the finals, it is simple. The fastest swimmer gets the the gold medal, second gets the silver medal, and third gets the bronze medal.
  • Finish times are taken to the hundredth (.00). Because of this, ties could (and do) occur if multiple swimmers finish a race with identical times. If a tie occurs in a preliminary (a tie for 16th) or semi-final (a tie for 8th) that would cause more than the appropriate number of swimmers to advance to the next round, a swim-off occurs between the tied swimmers.