Swimming Terms: The Glossary Every Swimmer Should Know (100+ Terms)

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Pool and distance terms

Length / lap

One end of the pool to the other is a length. In everyday pool talk “lap” usually means one length too, though some swimmers use lap to mean there and back. If a set says 4×50 in a 25m pool, that is two lengths per 50.

Short course (SC)

A 25 metre or 25 yard pool. Twice as many walls as long course, so times are faster. SCM = short course metres, SCY = short course yards.

Long course (LC / LCM)

A 50 metre pool, the Olympic standard. Fewer turns, slower times, and the format most serious meets use.

Lane rope

The floating line between lanes. The coloured sections near each end mark the last 5 metres in competition pools.

Flags / backstroke flags

The line of flags 5 metres from each wall, there so backstrokers can count strokes to the wall. Useful for everyone as the “head down, no more breaths” marker.

The T / the black line

The line on the pool floor and the T where it meets the wall. Used to judge the flip turn without lifting the head.

Pace clock

The large analogue or digital clock on deck. “Leave on the top” means start when the hand hits 60; “on the bottom” means 30.

Swimmer’s mile

1,650 yards, the longest short course yards event. It is about 1,509 metres, 94 percent of a real mile. See how many laps is a mile.

Training and set terms

How to read a set: 8×50 free build on 1:00 means eight 50s of freestyle, each starting easy and finishing fast, leaving every minute. 4×100 (30 sec rest) means four 100s with 30 seconds rest after each. Most of the terms below are the shorthand inside those lines.

Set

A group of repeats with a shared purpose, e.g. the main set. A session is usually warm-up, pre-set or drills, main set, cool-down.

Repeat / rep

One swim within a set. 8×50 is eight repeats of 50.

Interval / on

The total time allowed for each repeat including rest. “8×50 on 1:00” means you leave every minute whatever you swam. Faster swimming earns more rest.

Rest interval (RI)

Fixed rest between repeats regardless of swim time. “8×50 with 20s rest” or “(20 sec rest)”. Pick a time frame rather than counting: if you swim your 100s in 1:20 and want 30 seconds rest, leave on 1:50.

Warm-up

The easy swimming, drills and build efforts that prepare you for the main set. Skipping it is the most common reason the first hard repeat feels terrible.

Main set

The part of the session that does the work. Everything else supports it.

Cool-down / swim down / warm-down

Easy swimming at the end to bring the heart rate down. “100 swim down” is a slow, relaxed 100.

Build

Start easy and get faster within the repeat. “4×100 build” means each 100 starts easy and finishes fast.

Build 1-4

Each repeat is faster than the last. The first is slowest, the fourth fastest.

Descend / descending

Same as build 1-4: get faster through the set. “6×200 descend 1-3” means two sets of three, each set getting faster.

Negative split

Swim the second half faster than the first. The opposite, a positive split, is what most swimmers do by accident.

Even split

Hold the same pace for every part of the swim. The target in most distance events.

Broken swim

A race distance swum in pieces with short rests, e.g. a broken 400 as 4×100 with 10 seconds rest, to practise race pace.

Max / max effort / sprint / all out

As fast as you can go. “2×25 max” is two 25s flat out.

@ 95% / at 90%

Effort as a percentage of your maximum. “50 @ 95%” is a near-sprint with a little control.

Moderate / easy / steady

Comfortable aerobic pace you could hold for a long time. Called zone 2 by cyclists and runners.

Hard / fast / strong

Above comfortable, clearly working, but not a sprint.

Race pace (RP)

The pace you want to hold in your target event. Race-pace sets practise that exact speed with rest.

Threshold

The hardest pace you can sustain for around 30 to 60 minutes. Roughly the same thing as CSS.

CSS (Critical Swim Speed)

Your threshold pace per 100, worked out from a 400 and a 200 time trial. The single most useful number for structuring training. Find yours with the CSS calculator.

CSS +5 / CSS −2

Pace relative to CSS in seconds per 100. CSS +5 is five seconds per 100 slower than threshold, a typical aerobic pace; CSS −2 is faster than threshold.

Time trial (TT)

A timed swim at maximum sustainable effort, usually 400 and 200, to measure fitness and set CSS.

Choice

Any stroke you like. “300 choice” is 300 of whatever you want.

Form / form stroke

Any stroke that is not freestyle: butterfly, backstroke or breaststroke. “200 form” is 200 of one of those.

IM (individual medley)

All four strokes in order: butterfly, backstroke, breaststroke, freestyle. A 100 IM in a 25m pool is 25 of each.

Medley / IM order / reverse IM

Medley order is fly, back, breast, free. Reverse IM is free, breast, back, fly, a common warm-up order because it finishes with the hardest stroke when you are warm.

Breathing 3/5 in 50s

Breathe every third stroke for the first 50 and every fifth for the second 50, alternating. A hypoxic (reduced-breathing) pattern.

Hypoxic

Sets with restricted breathing to practise breath control. Not the same as holding your breath; you still exhale continuously.

Min/max free

Freestyle with a maximal kick and slowed-down arms, to load the legs.

Repeat (–Repeat–)

Do the listed set again from the top.

Pull

Swim with arms only, usually with a pull buoy and sometimes paddles. “400 pull” means 400 with a buoy.

Kick

Swim with legs only, on a kickboard, on your back, or on your side. “8×50 kick” is leg work.

Drill

A deliberately modified version of the stroke that isolates one skill. “8×50 drill” means your choice of drill unless specified. See the swimming technique guide for the ones we use.

Drill/swim

Half the repeat as a drill, half as full stroke, so the feeling transfers. 50 drill/swim is 25 drill, 25 swim.

Scull

Small figure-eight hand movements with the forearms, used to develop feel for the water and the catch.

Streamline

The tightest body position: arms extended overhead, one hand over the other, head between the arms, legs together. Used off every wall and start.

Breakout

The first strokes after the push-off or dive as you come to the surface.

Underwater / dolphin kicks off the wall

The kicks taken in streamline after a push-off before the breakout. Two or three is plenty for most adults.

Flip turn / tumble turn

The somersault turn in freestyle and backstroke. Same thing, American and Australian names. Step by step in our flip turn guide.

Open turn / touch turn

The turn used in butterfly and breaststroke (and by freestylers who do not flip): touch the wall, tuck, push off.

Volume / yardage / metreage

Total distance swum in a session or week. “A 3k session” is 3,000 metres.

Taper

Reducing training volume in the one to three weeks before a big race so you arrive fresh.

Swim block

A period of several weeks with a consistent, structured training focus. See how to swim faster.

Technique terms

Body position

How the body sits in the water: ideally long, horizontal and close to the surface with hips up. The foundation of every stroke.

Posture / body tautness

A firm, connected body from head to feet: shoulders down and back, belly button drawn in, glutes lightly on. The term body tautness comes from coach Gerry Rodrigues.

Rotation

Rolling the body along its long axis in freestyle and backstroke, driven from the hips, so each arm gets a longer, stronger pull.

Over-rotation

Rolling too far, usually when breathing, so the hips swing and the legs scissor. A very common fault.

Catch

The start of the propulsive phase: fingertips down, forearm vertical, elbow high, pressing the water back. The most important part of the pull.

High elbow / early vertical forearm (EVF)

The catch position where the elbow stays high and the forearm gets vertical early, so the whole forearm and hand push water backward. The thing every freestyler is chasing.

Pull

The underwater propulsive phase of the arm stroke, from catch to exit.

Recovery

The arm’s travel over the water from exit to entry.

Entry

Where and how the hand goes into the water, ideally in front of the shoulder, fingertips first.

Extension

Reaching forward after the entry before the catch begins. Over-reaching is reaching so far the shoulder drops and the body position breaks.

Crossover

The hand entering or pulling across the centre line of the body. Causes snaking and a weak catch.

Front quadrant

Having one hand in front of the head at all times in freestyle, so the stroke never has both arms behind the shoulders.

Catch-up stroke

A drill (and sometimes a fault) where one arm waits in front until the other arrives. As a drill, it teaches extension; as a habit, it kills rhythm.

Windmill / straight-arm

Arm recovery with a straight arm over the water, used by sprinters and open water swimmers. Not wrong, just a style with trade-offs.

Stroke rate (SR) / tempo

Strokes per minute. Higher is not better or worse; it is a gear. Lifting rate slightly while holding stroke length is one of the fastest speed gains.

Distance per stroke (DPS) / stroke length

How far you travel per stroke. The product of stroke rate and stroke length is your speed.

Stroke count

Strokes per length. A useful efficiency check, but chasing a low count by over-gliding is a common trap.

SWOLF

Strokes plus seconds for one length. Lower is more efficient. Many watches report it.

Tempo trainer

A small waterproof metronome worn under the cap that beeps at a set stroke rate or pace.

Bilateral breathing

Breathing to both sides, usually every third stroke. Good for symmetry and open water sighting.

Two-beat / six-beat kick

How many kicks per arm cycle. Two-beat is the distance swimmer’s economical kick; six-beat is the sprinter’s propulsive kick.

Kick timing

Coordinating the kick with the catch on the same side. A two-beat kick timed with the catch connects the stroke.

Glide

The streamlined travel phase after a kick in breaststroke, or after a push-off. Breaststroke speed lives here; see how to swim breaststroke.

Undulation / body wave

The chest-to-feet wave motion in butterfly. Starts at the chest, not the head; see how to swim butterfly.

Pull-out / underwater pull

The one allowed underwater arm pull and kick after a breaststroke start and turn.

Sighting

Lifting the eyes just above the water in open water to check direction, usually combined with a breath.

Feel for the water

The ability to sense pressure on the hands and forearms and adjust the stroke to it. Built through sculling, drills and swimming without a watch.

Equipment terms

Pull buoy

A foam float held between the thighs to lift the legs and isolate the arms. How to use it well: pull buoy guide.

Paddles

Plastic plates worn on the hands to add resistance and feedback to the catch. Size matters; larger is not better.

Kickboard

A foam board held in the hands for kick sets.

Fins

Flippers. Short fins keep the kick tempo realistic; long fins give more propulsion. Great for learning butterfly and for body-position work.

Snorkel (centre-mount)

A front-mounted snorkel so you can swim freestyle without turning to breathe, isolating stroke mechanics.

Tempo trainer

See stroke rate above.

Drag suit / parachute / band

Resistance tools: an old baggy suit, a small parachute, or a band around the ankles to stop kicking and load the arms.

Mirrored / smoke / clear lenses

Goggle tints. Mirror for bright sun, smoke as the in-between, clear for indoors and low light.

Anti-fog

The treatment that stops goggles fogging. Most goggles use a coating that wears off; NanoClear bonds it into the lens itself.

Gasket

The soft seal between the goggle and your face. Shape and softness decide comfort and leaks.

Nose bridge

The piece joining the two goggle eyecups. Interchangeable bridges let one goggle fit narrow and wide faces.

Swedes / Swedish goggles

Minimal hard-plastic racing goggles with no gasket, assembled by the swimmer. Beloved by racers, brutal for beginners.

Racing and open water terms

Masters swimming

Organised competitive swimming for adults, typically from age 18 or 25 up, in five-year age groups.

Age group

Youth competitive swimming, grouped by age. Also the five-year bands used in Masters.

Heat

A group of swimmers racing at the same time. Big events run many heats.

Seed time

The time you enter a meet with, used to place you in heats and lanes.

PB / PR

Personal best / personal record.

Split

The time for a segment of a race, e.g. the 50 splits of a 200.

Touchpad

The electronic pad on the wall that records your finish time.

DQ

Disqualification for a stroke, turn or start infraction.

False start

Leaving the block before the signal. One and you are out in most competitions.

Relay takeover

The exchange between relay swimmers, where the next swimmer may leave as the previous one touches.

Open water

Any swim in a lake, river or sea rather than a pool.

Wetsuit legal / non-wetsuit

Whether the water temperature allows (or requires) wetsuits in a triathlon or open water race.

Drafting

Swimming directly behind or beside another swimmer to save energy in open water.

Mass start / rolling start / wave start

How an open water race begins: everyone together, in a continuous stream, or in groups.

Washing machine

The chaotic first few hundred metres of a mass-start triathlon swim.

T1

The first transition in a triathlon, from swim to bike. Triathletes count the swim exit and run to the bike as part of the swim.

Channel swim / marathon swim

Open water swims of 10 km and beyond, often with a support boat.

Missing a term you’ve heard on deck? The workouts page explains the notation used in our sessions, and the technique guide covers the stroke vocabulary in depth.

Frequently asked questions

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