Swimming Terms
This glossary defines non-branded swimming terminology: stroke and technique, pool and open-water conditions, and training terms and equipment. Mass start, negative split, and interval training are cross-referenced to the Running glossary page rather than redefined here, since those concepts apply identically across sports.
Quick answers
What is an aerobic set in swimming?
An aerobic set is a group of repeats swum at a steady, sustainable effort intended to build endurance rather than speed.
What is backstroke?
Backstroke is a competitive stroke swum on the back, using an alternating overarm action and a continuous flutter kick.
What is bilateral breathing?
Bilateral breathing is a breathing pattern that alternates sides, typically every third stroke, rather than favouring one side.
What is body position in swimming?
Body position is the alignment of a swimmer’s torso, hips, and legs in the water, a primary factor in reducing drag.
What is body roll (rotation) in swimming?
Body roll, or rotation, is the rolling motion of the torso around its long axis during freestyle and backstroke, which lengthens the stroke and assists breathing.
What is breaststroke?
Breaststroke is a competitive stroke swum with a simultaneous, symmetrical arm pull and a whip kick, performed with the body largely facing down.
What is a build set?
A build set is a group of repeats in which effort or speed increases progressively within each repeat.
What is a buoy course?
A buoy course is the marked route in open water, defined by a sequence of buoys swimmers must pass.
What is butterfly (swimming stroke)?
Butterfly is a competitive stroke swum with a simultaneous overarm recovery and a dolphin kick, performed with an undulating body motion.
What is the catch in swimming?
The catch is the beginning of the underwater arm pull, where the hand and forearm establish purchase on the water before driving backward.
What is a catch-up drill?
A catch-up drill is a technique drill in which one arm remains extended in front until the recovering arm reaches it before the next stroke begins.
What is chop (open water)?
Chop is small, irregular surface waves in open water, typically caused by wind or boat traffic.
What is cold-water shock?
Cold-water shock is the involuntary gasp and rapid breathing response triggered by sudden immersion in cold water, a significant open-water safety risk.
What is CSS (critical swim speed)?
CSS, or critical swim speed, is an estimated sustainable swimming pace derived from timed trials, used to set training paces.
What is a current (open water)?
A current is the directional flow of water in open water or tidal venues, which can assist or hinder a swimmer depending on direction.
What is a deep water start?
A deep water start is a race start in which swimmers begin treading water rather than diving or wading in from a beach or pool wall.
What is a descending set?
A descending set is a group of repeats swum progressively faster, or at progressively lower times, across the set.
What is dolphin kick?
Dolphin kick is an undulating kick performed with both legs moving together, characteristic of butterfly and used underwater off starts and turns.
What is drafting in open water swimming?
Drafting in open water is swimming close behind or beside another swimmer to exploit the reduced resistance in their wake, a distinct tactic from cycling drafting due to the different hydrodynamics involved.
What is a drill in swimming?
A drill is a swimming exercise isolating one element of technique, performed at reduced speed to reinforce correct movement.
What is early vertical forearm (EVF)?
Early vertical forearm describes positioning the forearm vertically early in the underwater pull, maximising the surface area pushing water backward.
What are swim fins used for?
Fins are swim training equipment worn on the feet to increase propulsion and support technique or speed work.
What is a flip turn (tumble turn)?
A flip turn, also called a tumble turn, is a turn performed by somersaulting into the wall and pushing off in the opposite direction without touching the wall by hand.
What is flutter kick?
Flutter kick is a continuous, alternating up-and-down leg kick used in freestyle and backstroke.
What is freestyle (swimming stroke)?
Freestyle is the fastest competitive stroke, swum with an alternating overarm action and a flutter kick, and the default stroke in most open-water and triathlon swimming.
What is hand entry in swimming?
Hand entry is the point at which the hand re-enters the water at the start of the stroke, ideally in front of the shoulder with minimal splash.
What is a high-elbow catch?
A high-elbow catch is a catch technique in which the elbow stays higher than the hand and forearm, improving the pulling surface presented to the water.
What is a hypoxic set?
A hypoxic set is a set performed with reduced breathing frequency, historically used to build breath control, though its aerobic training value is disputed in modern coaching.
What is IM (individual medley)?
IM, or individual medley, is a race format in which a swimmer completes all four competitive strokes in a fixed order, typically butterfly, backstroke, breaststroke, then freestyle.
What is interval training in swimming?
Interval training in swimming is defined in full under Running, and applies to swimming as repeated efforts separated by rest.
What is a kickboard?
A kickboard is a buoyant board held with the arms to isolate leg kick during drills.
What is a lane rope?
A lane rope is the floating rope dividing adjacent lanes in a pool, which also dampens surface waves.
What is LCM (long-course metres)?
LCM, or long-course metres, refers to a 50-metre pool, the standard length for Olympic competition.
What is long course swimming?
Long course describes racing or training in a 50-metre pool.
What is the main set in a swim workout?
The main set is the central, highest-priority portion of a swim session, typically following a warm-up and preceding a cooldown.
What is a mass start in swimming?
A mass start in swimming follows the same definition as in Running, a single start in which every competitor begins at the same time.
What is a negative split in swimming?
A negative split in swimming follows the same definition as in Running, the second half of a swim completed faster than the first.
What is an open turn in swimming?
An open turn is a turn performed by touching the wall with the hand, used in breaststroke and butterfly where a flip turn is not permitted.
What are swim paddles used for?
A paddle is a hand-worn training tool that increases resistance and surface area to build pulling strength.
What is a pace clock?
A pace clock is a large, visible clock mounted poolside used to time sets and control send-off intervals.
What is the pull in swimming technique?
In swimming technique, the pull is the propulsive underwater arm phase of the stroke, distinct from the pull buoy equipment used to isolate it in training.
What is a pull buoy?
A pull buoy is a buoyant foam device held between the thighs to support the legs and isolate the arms during pull-focused training.
What is the pull phase in swimming?
The pull phase is the portion of the stroke cycle in which the arm drives backward through the water to generate propulsion.
What is a push-off in swimming?
A push-off is the propulsive action of pressing off the pool wall with the feet, typically performed in a streamlined position after a turn or start.
What is recovery in swimming stroke technique?
In stroke mechanics, recovery is the phase in which the arm exits the water and moves forward through the air back to the entry point, distinct from recovery in the training sense of easy effort between hard sessions.
What is a rest interval in swimming?
A rest interval is the planned pause between repeats within a set, either a fixed duration or the remainder of a send-off time.
What is SCM (short-course metres)?
SCM, or short-course metres, refers to a 25-metre pool measured in metres.
What is SCY (short-course yards)?
SCY, or short-course yards, refers to a 25-yard pool, the standard competition length in the United States.
What is sculling in swimming?
Sculling is a technique drill using small, repeated hand movements to build feel for the water and pressure through the pull.
What is a send-off in swimming?
The send-off is the clock time at which each repeat in a set begins, commonly expressed as “on the” a given minute mark.
What is short course swimming?
Short course describes racing or training in a 25-metre or 25-yard pool.
What is sighting in open water swimming?
Sighting is the technique of briefly lifting the head to look forward while swimming, used in open water to navigate a course; alternating which side the head lifts to is known as bilateral sighting.
What is a swim snorkel used for?
A training snorkel is a centrally mounted breathing tube that allows a swimmer to maintain head position and stroke mechanics without turning to breathe.
What is streamline position in swimming?
Streamline is the extended, narrow body position held off the wall after a start or turn to minimise drag.
What is stroke count?
Stroke count is the number of arm strokes taken to cover a set distance, typically one length of a pool.
What is stroke length (distance per stroke)?
Stroke length, or distance per stroke, is the distance travelled for each individual stroke cycle, a key efficiency measure.
What is stroke rate in swimming?
Stroke rate is the number of strokes taken per minute.
What is a swim set?
A swim set is a defined group of repeats performed with a specified distance, interval, and purpose within a session.
What is SWOLF?
SWOLF is a swimming efficiency score combining the time and stroke count for a length or set distance, with a lower score indicating greater efficiency.
What is a tempo trainer?
A tempo trainer is a small, clip-on device that emits an audible beep to help a swimmer hold a target stroke rate.
What is a threshold set in swimming?
A threshold set is a group of repeats swum at an effort close to a swimmer’s CSS or lactate threshold pace.
What are tidal and wind-affected conditions in open water swimming?
Tidal and wind-affected conditions describe how tide and wind alter current, chop, and course difficulty in open water, factors swimmers must account for beyond baseline current and chop.
What is the underwater phase in swimming?
The underwater phase covers the portion of a length spent submerged after a start or turn, before surfacing to begin normal stroke.
What is a wave or rolling start in swimming?
A wave or rolling start releases swimmers in staggered small groups rather than all at once, common in larger open-water and triathlon events as an alternative to a single mass start.
What does wetsuit-legal mean?
Wetsuit-legal describes a race or water condition, typically defined by a water temperature threshold, under which wetsuits are permitted or required under competition rules.
