Grunion Glossary

Swimming has it's own special language. This glossary will help new swimmers understand that odd sounding jargon they might encounter during a practice session.

Swimming, like every other vocation and specialized subject, has it's own jargon, it's own lingo. If you've been swimming for a while, that jargon has become second nature to you.

Take for example, the sentence:

We did a set of 10x100 on the 1:30, negative-splitting each 100 and descending the set.


For the swimming veteran, that sentence is crystal clear. For the newbie, however, it is a bewildering maze of esoteric jargon, a Kabalistic mystery beyond the ken of normal human beings. It might as well be Sanskrit. Fear not, newbie! Understanding the language of swimmers is actually quite simple, once you become acquainted with the more common terms. To help you along the path to aquatic enlightenment, we've developed the following Grunion Glossary.

10 x 100

This number describes the number of sets times the distance of each set. The pool is 25 yards long. If you were to swim from one end of the pool to the other end, you have completed 1x25. If you were to make it a round trip and swim from one side to the pool and back you have swum 50 yards, or 1x50. If you were to swim 2 round trips then you have swum 100 yards or 1x100. If you were to swim 100 yards ten times, then you have done 10x100!


Swimmers use a pace clock to time their sets. They always speak in minutes and seconds. When coach tells you to swim a set on "the one thirty" he is saying that you have 1 minute, 30 seconds to complete the set, or 1:30

Ascending Interval

A set during which the interval (swim time plus rest) increases with each repeat. An ascending interval set of 5x100 may have send-offs at 1:40, 1:45, 1:50, 1:55 and 2:00.

Ascending Set

A series of swims of the same distance whereby the swim time increases with each successive repeat. The swimmer's times on an ascending set of 4x50 on a 1:00 minute interval may be :40, :42, :44, :46.

Bilateral Breathing

The process of breathing on alternate sides during freestyle, or breathing in a pattern of odd-numbered single arms strokes, such as breathing every third or fifth strokes.


The reading on a pace clock that corresponds to a seconds reading of "30". Typically a coach will instruct swimmers to leave (begin) "on the bottom" or "on the 30". Also see "Top"

Build-up Swims

Specific distances over which the rate of speed is gradually increased. For a build-up 100 yard swim, the swimmer starts at a slow speed, gradually building to maximum or near-maximum speed at the end of the 100.

Circle Pattern Swimming

An oval shaped path followed in a lane that will accommodate multiple swimmers. In the United States, circle pattern swimming implies swimming on the right hand side of the lane at all times. In other parts of the world swimmers use the left hand side of the lane.


A series of sets. Multiple sets swum one after another comprise a cycle. An example of a complete cycle would be swimming 2x100, followed by 4x100, followed by 8x50.

Descending Interval

A set during which the interval (swim time plus rest) decreases with each repeat. A descending-interval set of 5x100 may have send-offs of 2:00, 1:55, 1:50, 1:45 and 1:40.

Descending Set

A series of swims of the same distance whereby the swim time decreases with each successive repeat. The swimmer's times on a descending set of 4x50 on 1:00 may be :46, :44, :42, :40.


Swimming in the wake or behind another swimmer. It has been proven that a swimmer benefits by swimming roughly 10 meters or less behind a leading swimmer.


An exercise designed primarily to improve the technique of a swimmer. Many drills focus on a single aspect of a stroke or stroke technique. Often Coach may say Drill 25, then Swim 25 which means do a drill stroke for 25 yards, then do the the full stroke for the next 25 yards.

Even Split

Swimming the first and second halves of a swim in identical times.


Training with a limited supply or intake of oxygen. An example of hypoxic training is swimming 4x25 freestyle on 1:00 without breathing during the swimming portion of the set.


A specific time period that includes both the active swimming and subsequent rest. A set of 10x50 yards on an interval of 1:00 means that the swimmer leaves from the starting wall every minute. If it takes the swimmer 45 seconds to complete 50 yards, the rest following the swim is 15 seconds.


Propelling by use of the legs only. Kicking sets or exercises often include the use of kickboards and/or fins.

Lactate Tolerance Training

Training during which the body experiences a lack of oxygen, resulting in the production of lactic acid. During the production of lactic acid, the swimmer typically experiences a burning or aching sensation in the muscles.


In swimming, a lap may refer to either one or two lengths of the pool. A length is the distance from one side of the pool to the other, typically 25 yards or 50 meters. Coaches and swimmers communicate in terms of "lengths" rather than "laps" to eliminate any confusion over intended distances.

Long Course Meters (LCM)

A pool which is 50 meters long. Since there are less flip turns in this type of pool, the longer events can be very challenging.

Long Course Yards (LCY)

A pool which is 50 yards long.

Negative Split

A swim during which the second half is completed faster than the first half.


A swim during which only the arms are used. Pulling generally implies the use of a pull buoy, a flotation device placed between the legs. Hand Paddles are also often used.

Race Pace Training

Swimming in a workout that simulates the speed at which a swimmer will compete.

Repeat (Rep)

A single swim in a set, also referred to as a repetition. A set of 20x25 on :40 contains 20 repeats of 25 yards. Also referred to as a "Rep"

Rest Interval

A specified amount of rest between two swims in a set. A set of 5x200 with a 1:00 rest interval means that a swimmer rests for 1:00 after the conclusion of each 200 regardless of the 200 swim time.


Similar to interval, a send-off of 2:00 means that the swimmer starts each swim two minutes apart. Send-off may also refer to the actual position or reading on a pace clock, such as a send-off on the "top" or "bottom".


A number of repetitive swims (repeats) at specific distances that typically involve an interval or rest interval. There is virtually a limitless number of sets that vary in number of repeats, distance or repeats and rest or swim interval. An example of a basic set is 10x100 yard swims on a 1:30 interval.

Short Course Meters (SCM)

A pool which is 25 meters long. Since meters are a little longer than yards, this is a longer distance than a Short Course Yards event and that should be accounted for when looking at times.

Short Course Yards (SCY)

A pool which is 25 yards long. Since yards are a little shorter than meters, this is a shorter distance than a Short Course Meters event and that should be accounted for when looking at times.


The time for a portion of a race or swim. Also called "Split Time".


The method of aligning the body so as to reduce resistance in the water.

Stroke Drill

See "Drill"


Training period designed to produce a peak performance by a swimmer in a competition. A taper generally follows a higher-intensity phase or phases, and is a phase during which a swimmer grows stronger through rest and recovery.


The reading on a pace clock that corresponds to a seconds reading of "0" or "60". Typically, a coach will instruct swimmers to leave (begin) "on the top" or "on the 60".


Easy to moderate swimming following an intensive effort or race. The purpose is to rid the body of excess lactic acid and to reduce heart rate and respiration. May also be referred to as "recovery swimming" or "active rest".


A period of swimming designed to acclimate the swimmer for a workout or a race. During warm-up, a swimmer generally experiences an increase in heart rate and respiration.