If you don’t have a swim training background or are heading to the pool for the first time, then swimming lingo can seem like a foreign language. But even if you’re a novice or a front crawl improver, knowing your way round a pool training session and how a pace clock works can help fast-track your improvements. Our partners at Straight Line Swimming explain some commonly used terms and abbreviations in pool training sessions.

Training session structure

A training session is divided into sets. Typically, a session will consist of a Warm-Up, Sub-Set or Prep-Set, Main Set and Cool Down.

Type of training session

Different training sessions have different goals. For a balanced training regime swimmers should divide their training into technique, speed, distance and heart-rate sessions. It is important to set each session with a particular goal and for your swimmer to understand the benefit of each session.

Training seasons

An athlete’s overall training plan is known as a training season. A season could be four years if you are an Olympic athlete, a year or a block of sessions with a particular goal like increasing distance, speed or technique. The season is divided into shorter cycles that build towards your specific goals. 

Basic session lingo

BR – Breaststroke

Back or BS – Backstroke

FC – Front crawl

Fly – Butterfly

FS or Free – Freestyle. Usually front crawl, but any stroke

IM – Individual Medley (all four strokes in order Butterfly, Backstroke, Breaststroke, Front crawl)

Kick – Using only your legs (often done using a kickboard (float))

Pull – Using only your arms (with a pull buoy)

Easy – a slow easy pace

Hard – swimming hard but at a pace maintainable for the duration of the set

Max – as fast as you can possibly swim

Deciphering a session

Sets are structured in intervals or repetitions. 10 x 100 means ten lots of 100 metre swims (four lengths of a 25m pool). After each 100m the swimmer should rest. This can be noted in two ways. Either:

10 x 100, 15 secs rest (15 seconds rest after each 100m swim).

Or:

10 x 100 off 1.30. Using 1.30 as an example time, this means that the swimmer has 1 minute 30 seconds to complete each 100m swim and rest. The next swim will start 1.30 after the preceding swim started, no matter how much (or little!) rest the swimmer has had.

In a training session swimmers will use the pace clock commonly seen on the wall of swimming pools. ‘On the top’ means the first swimmer in the lane will start when the hand is at 12. Following swimmers will generally go intervals of five to ten seconds afterwards. ‘Black top’ is when the black hand is at 12, ‘red top’ is when the red hand is at 12.

Build

Swimming faster by the end of the repetition. ‘5 x 200 build’ would mean you would swim five lots of 200m, getting faster throughout the rep. Think of it as speeding up throughout the rep.

Descend

Getting faster over the duration of a set, eg. 4 x 50m descend to max

Ascend

Getting slower over the duration of a set.

Negative Split

Swimming faster on the second half of a repetition. For example, you swim 200m in 3 minutes, the first 100m in 1.45 and the second in 1.15.

Hypoxic

Breath control training – for example, sets where you breathe every 3, 5, 7 and 9 strokes.

CSS

Critical Swim Speed. Used in threshold pace training. The best pace you can maintain for 1500 metres. Calculate by doing a 400m time trial followed by a 200m time trial. Google ‘CSS Calculator’ for an easy way to work out your swimmers’ paces!