Swim sessions: structure, drills and the move to triathlon
On this page
How a session is built
Swim England's pool training plan gives every session a warm-up, skill development, a main set and a swim down.1 U.S. Masters Swimming describes the same structure: a warm-up, a drill or kick set, the main set that sets the theme of the workout, and a cool-down. Masters workouts usually last one hour to an hour and a half.2
The vocabulary you will see on the board:2
- Set: a group of repetitions with a purpose. It can be swimming, drills, pulling (often with a pull buoy and paddles) or kicking.
- Interval: "5 x 100 on 2:00" means leaving every two minutes. Your rest depends on how long the swim takes.
- Rest interval: "5 x 100, RI :10" means ten seconds of rest after every repetition, whatever the swim time.
The ratio of effort to rest sets the type of work: a maximum-speed set needs long rests, a distance-pace set needs very little.2
Levels and contexts: what changes
The structure stays the same. Volume changes most. Swim England's plan starts at 12 lengths (300 m) in session 1, reaches 38 lengths (950 m) in session 10, 1000 m in session 11 and 80 lengths of a 25 m pool (2000 m) in session 20. The federation says to pick where to start by experience, even starting from the first session and repeating it, and to notice how it felt.1 Sessions 2 onwards are for Swim England members (free Just Swim registration): we report only the structure and progression stated on the public page.
| Context | What the source says |
|---|---|
| Starting or returning | Pick a short session from the plan and repeat it; volume from 300 m up in Swim England's example.1 |
| Already swimming regularly in a pool | Same structure, longer sessions in the plan (up to 2000 m). In a Masters group each set has a purpose stated by the coach.12 |
| Preparing for open water | For newcomers Swim England points to an organised session, never alone: the coach may include starting, pack swimming, drafting, sighting, turning and finishing.5 |
Drills described by Swim England
Breathing in three steps. Swim England proposes them in this order.3
- Standing in the water, bend your knees until your face is under, exhale slowly while counting until your lungs are empty; six repetitions.
- With a kickboard, face in the water, exhale counting to six; at six turn your head to the side for one sharp breath, then put your face back in and exhale again counting to six.
- Full stroke, relaxed arms, breathing every three strokes; if it does not feel comfortable, go back to drills 1 and 2.
Breathing every three strokes is described by Swim England as a standard technique that alternates sides; the text adds that regularity is not fixed and you breathe when you need to.6
Sighting. The pool drills for learning to look ahead are on the sighting page.
Pull buoy. It gives the hips buoyancy and lines the body up: you can focus on the rest of the stroke, and a triathlete with tired legs after a run or ride can keep working on the upper part of the stroke. If it works too well the hips ride too high and it can build poor technique; with a weak kick it can make you rely on the arms. The source recommends knowing what you want to improve and choosing the right size before using it.4
Stroke rate, stroke length and body position are in Technique: stroke rate and stroke length.
Teaching example, not a plan
A session built on the structure above, in a pool:
- Warm-up: easy swimming, no intervals.
- Skills: breathing drills 1, 2 and 3 in order, going back if you are not comfortable.
- Main set: repetitions of a distance you can swim entirely with clean technique, with an interval or rest interval chosen with a coach.
- Swim down: easy swimming.
There are no distances, paces or intervals in numbers: no source we read validates them for an amateur, and yours depend on how you swim. For a pace estimate from two trials there is the CSS calculator, which gives no zones. For the type of intensity swimmers use, see Training methods.
From the pool to triathlon
If the race is a triathlon, the swim ends in the transition area. From the World Triathlon rulebook (official version with amendments up to April 2026):7
- Wetsuits, section 4.2. Age-group from the youngest category to 55-59: up to 1500 m the wetsuit is forbidden at 22 °C and above; from 1501 m it is forbidden at 24.6 °C and above. For 60-64 and older, 24.6 °C applies to all distances. In every table it is mandatory at 15.9 °C or below. Between the two values the table states neither a ban nor an obligation.
- First transition, section 7.1. The wetsuit can be fully removed only in the designated area or at your own spot; the upper part and arms can be undone earlier, as long as the torso stays covered. Shoes, glasses, helmet and other bike gear can be placed on the bike in T1. The helmet must stay fastened from when you take the bike off the rack until you have racked it and let go after the bike segment. You do not ride inside the transition area: you mount after the mount line. Marking your position with towels or objects is forbidden.
These are the rules of World Triathlon races. Federations and organisers can adopt them with changes: for your race, the event's own rules apply. For race pacing of the swim see Race pacing and the swim in triathlon. For wetsuits and cold water see Open water and safety.
What we know and what we do not
We know how federations and clubs structure a session, which breathing drills Swim England proposes and what the World Triathlon rulebook says about wetsuits and the first transition. We publish no sessions in numbers and no weekly programmes: no source validates them for an amateur, and a session built for you needs someone who sees you swim.
How we reviewed it
Reading of six Swim England and U.S. Masters Swimming pages and of sections 4.2 and 7.1 of the World Triathlon rulebook.
Limits. Non-experimental guidance, not studies on amateurs; Swim England sessions 2-20 are members-only; the rulebook covers World Triathlon races, other events can differ.
Sources
- Swim England. Swimming Fitness Training Plan: 20-session pool programme (2017). swimming.org (public page read; sessions 2-10 and 12-20 are members-only)
- U.S. Masters Swimming. Swimming 101: How to start swim training as an adult. usms.org (page read)
- Swim England. Front crawl breathing drills (2018). swimming.org (page read)
- Swim England. Fitness Booster: how the pull buoy is the go-to piece of equipment (2019). swimming.org (page read)
- Swim England. Tips for practising in open water (2018). swimming.org (page read)
- Swim England. Improving your front crawl technique (2018). swimming.org (page read)
- World Triathlon. Competition Rules, sections 4.2 and 7.1 (official PDF, version of 13 December 2025 with amendments highlighted up to 29 April 2026). PDF · triathlon.org (text read)
Sources rechecked on 28 October 2026. Wolf Lab is not affiliated with Swim England, U.S. Masters Swimming or World Triathlon.