Pool training
How do you read a triathlon swim workout?
Read a pool swim set in this order: repetitions, distance and units, stroke, effort, then rest instructions. Fixed rest starts after you finish each swim. A send-off includes both swimming and rest before the next start. Check the pool length and your coach's notation before turning the set into lengths or clock times.
By the TriElite team · Published 2026-10-16
Explore TriElite on the App Store →
What does 4 × 75 mean in a swim workout?
It means four separate swims of 75 units each. Confirm whether the workout uses metres or yards: the numbers alone do not say. A stroke, effort instruction and rest rule complete the set. US Masters Swimming describes this order as the usual way coaches write repetitions.
For a reading example, take '4 × 75 metres freestyle, 15 seconds rest between repeats'. Each repeat is 75 metres and the four swims total 300 metres. This example explains notation, not what you should swim today.
US Masters Swimming: How to Write a Swimming Workout (11 January 2023)
How many pool lengths is each repeat?
Divide the repeat distance by the pool length using the same units. A 75-metre repeat in a 25-metre pool is three one-way lengths. A 75-yard repeat in a 25-yard pool is also three lengths, but covers a different distance. Do not silently treat yards as metres.
Write down the pool length before counting. US Masters Swimming notes that people use 'lap' differently: some mean one length, others mean out and back. Asking for the distance and number of one-way lengths avoids that ambiguity.
A repeat that does not divide into whole lengths needs clarification. For example, 75 metres does not end at a wall after a whole number of 50-metre lengths. Ask the coach how to adapt the set to that pool.
What does RI :15 or 15 seconds rest mean?
RI means rest interval. With 15 seconds of fixed rest, finish the repeat, rest for 15 seconds, then begin the next one. The start time changes with how long you take to swim. US Masters Swimming distinguishes this from leaving on a fixed send-off.
Using the 75-metre reading example: start at 0:00 and finish at 1:35, then leave again at 1:50. If that swim instead takes 1:45, leave at 2:00. In both cases the rest is 15 seconds. Keep any separate instruction about recovery after the final repeat.
What does swimming on a 2:00 send-off mean?
A 2:00 send-off means starting a new repeat every two minutes. Swimming and rest share that time. For four repeats starting at 0:00, the departures are 0:00, 2:00, 4:00 and 6:00. They do not move later when a swim takes longer.
If a repeat takes 1:35, there are 25 seconds before the next departure. If it takes 1:45, there are 15 seconds. These are arithmetic examples, not pace targets. US Masters Swimming explains that fixed rest and send-offs are different ways to specify a set.
Distinguish the last departure from the last finish. Four repeats on 2:00 have their final start at 6:00; if the last swim takes 1:35, it finishes at 7:35. An eight-minute block includes time after that finish. Read any following recovery instruction rather than assuming it.
US Masters Swimming: How to Write a Swimming Workout (11 January 2023)
How do you count rounds and the whole workout?
Read the brackets before adding the distance. 'Two rounds of 4 × 75 metres' contains eight 75-metre swims: 600 metres. A rest instruction between rounds is separate from rest between repeats. Check both before starting.
Add the warm-up, drills and cool-down separately if you need the full session distance. A 300-metre main set does not describe the whole workout. Keep a small poolside note with the round number, repetitions completed and the next departure time; use the facility's rules for anything you bring onto the deck.
Common mistakes when reading swim workouts
Tell the coach where the problem occurs: the distance, stroke, effort or time available for rest. Ask which instruction to change. US Masters Swimming describes adapting repeat distance or number when swimmers need different send-offs; the printed interval is not a universal target for every swimmer.
Do not invent a harder effort to make an unclear set fit. Confirm its purpose and an appropriate version before continuing. If you are learning to swim, get pool instruction rather than relying on written shorthand. TriElite is an iPhone training companion; an app does not replace that instruction or a coach's explanation of the set.
US Masters Swimming: How to Write a Swimming Workout (11 January 2023)
Keep reading
Sources and further reading
Sources reviewed 16 October 2026. US Masters Swimming's workout-writing article is by Terry Heggy, dated 11 January 2023; its adult-training guide explains pool lengths, rest intervals and pace-clock conventions. The calculations here are original reading examples, not prescribed sessions, fitness tests or evidence of open-water readiness. Ask the plan author about notation or adaptations specific to your workout.
Frequently asked questions
Does 8 × 50 mean 400 metres?
Only if the workout is written in metres. Eight 50-metre repeats total 400 metres; eight 50-yard repeats total 400 yards. Confirm the units and the rest instruction.
Is a 2:00 interval two minutes of rest?
When 2:00 is the send-off, it includes the swim and the remaining rest before the next start. An instruction explicitly giving two minutes of rest begins after you finish swimming. Ask when the notation is unclear.
Can I use a yard workout in a metre pool?
Ask how the distances and send-offs should be adapted. Keeping the same number of lengths changes the distance, so it does not reproduce the original workout exactly.
Build your week around your race and the time you actually have.
Download TriElite on the App Store