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Brick workouts for triathlon: how long, how often and sample sessions

By the Tuffr team · Last updated · 9 min read

A brick workout is a bike ride followed straight away by a run, so your legs learn what running off the bike feels like. Do one a week from about week 5 of a plan: 10 to 20 minutes of running after a 60 to 90 minute ride for sprint and olympic, a little longer for half distance.

What is a brick workout?

A brick is two sports back to back with no real break between them, almost always a ride followed by a run. The name is a nickname for the way your legs feel in the first minutes of the run. A swim followed by a ride is also called a brick, but the bike-run version is the one that most plans use.

A brick is not a harder workout by definition. It is a rehearsal of one moment in the race, the change from cycling to running, and most of the work is in learning to handle it calmly. It sits next to your ordinary rides and runs and replaces neither.

Why does running after cycling feel so hard?

Running right after a ride costs more energy and feels heavier. A review of the research puts the extra energy cost of running at 1.6 to 11.6 percent, depending on ability. In one small study, a 3000 m run took about 7 to 9 percent longer after 20 minutes of hard cycling than on its own (our arithmetic from the published times).

What the studies found (read 2026-11-06)
StudyWhoFinding
Millet and Vleck (2000), reviewStudies of olympic-distance triathletesRunning after cycling brings higher breathing rate and heart rate and a 1.6 to 11.6 percent higher energy cost. Most running mechanics are unchanged; the trunk leans further forward.
Bernard et al. (2003)9 well-trained triathletesAfter 20 minutes of cycling at more than 80 percent of VO2max, a 3000 m run took 626 to 638 s at three cadences, against 583 s alone. In the first 500 m, stride rate and speed were higher after 80 or 100 rpm than after 60 rpm.
Olcina et al. (2019)10 trained sprint and olympic triathletesIn the bike-run trial the athletes covered a shorter running distance than in the run-only trial, with a stride about 0.1 m shorter. Cadence and ground contact time did not change.

What the studies found (read 2026-11-06)

These studies show the cost of running off the bike. They do not show how much a brick session lowers it, and the samples are small. The advice below is our recommendation, based on common coaching practice and published beginner plans.

How long should a brick workout be?

For sprint and olympic, a brick is a 45 to 120 minute ride followed by a 10 to 25 minute run. The run is short on purpose, because the aim is to feel the change, not to run a hard session. These lengths are our recommendation. A published 12-week beginner plan uses 15 to 30 minutes of running after rides of 12 to 18 miles, and later 3 to 4 miles.

Brick length by purpose (our recommendation)
PurposeRideRunEffort
Feel the change (beginners, deload weeks)45 to 60 min easy5 to 10 minEasy
Weekly brick for sprint or olympic60 to 90 min15 to 20 minRide steady, run easy to steady
Race-effort brick (peak weeks)60 to 90 min with the last 20 min steady15 to 25 minLast 10 min of the run at race effort
Long brick for half distance (70.3®)2 to 3 h20 to 45 minSteady, run starts easy

Brick length by purpose (our recommendation)

The run of a brick rarely needs to be longer than 45 minutes. Long runs belong in their own session, when your legs are fresh.

How often should I do brick workouts?

Once a week is enough for most athletes, starting about a third of the way into a plan. A published 12-week beginner plan adds its first brick in week 4 and then repeats it in most later weeks. In our 12-week plan the first brick comes in week 5. Keep bricks short in deload and taper weeks.

  • First sprint or olympic (12 weeks): one brick a week from week 5, 10 to 20 minutes of running, shorter in deload and taper weeks. The week-by-week table is in the first triathlon plan.
  • Experienced sprint or olympic athletes: one brick a week in build and peak weeks, none in an easy week.
  • Half distance: one long brick in most build and peak weeks, plus a 10 minute run after other rides if your legs and schedule allow it. The phases are in the half-distance triathlon plan.
  • Do not stack a brick on the day after a hard run or a race simulation, and when you return from illness or injury restart with the short version.

Important

A run on legs tired from a long ride raises the load on your body. Start easy, and stop if you feel sharp pain, dizziness or unusual breathlessness. If an injury persists, see a doctor or a physiotherapist before you carry on.

What are sample brick workouts for sprint, olympic and half distance?

Here are six sample bricks. A sprint is a 750 m swim, 20 km ride and 5 km run, and the olympic distance is 1.5 km, 40 km and 10 km (World Triathlon). A half distance is a 1.9 km swim, 90 km ride and 21.1 km run. All sessions are our recommendation.

Sample bricks (our recommendation)
DistanceSessionRideRunWhat it trains
SprintEasy brick45 min easy10 min easyThe feeling of the change
SprintRace-effort brick60 min, last 20 min steady15 min, last 10 min at race effortRace pace off the bike
OlympicSteady brick90 min steady20 min easy to steadyEndurance and a calm start to the run
OlympicDress rehearsal20 min easy, then 40 min at race effort25 min, last 15 min at race effortRace effort and nutrition on the bike
Half distanceLong brick2.5 h steady30 min easy to steadyFuelling and the first 5 km of the run
Half distanceRace-effort brick2 h with 3 x 20 min at race effort30 min, last 15 min at goal run effortControlled pacing off the bike

Sample bricks (our recommendation)

Note

A notebook or any calendar is enough to log a brick as one ride and one run. Tuffr is an iPhone app that is not public yet; its closed beta is due by 30 November 2026. With the beta it will set a target for each leg, T1 and T2 and plan the training that closes the gaps, bricks included. The free triathlon calculator already turns your paces into a finish time.

How do I run well off the bike?

Spin your legs out at the end of the ride, change quickly and run the first few minutes easier than feels natural. The review lists possible causes for the heavy feeling, among them exercise intensity, fatigue of the breathing muscles, dehydration and depleted glycogen. You can manage the last two.

  1. In the last 2 to 3 minutes of the ride, shift to an easier gear and a higher cadence. In the cadence study the first 500 m of the run were quicker after 80 or 100 rpm than after 60 rpm, though total time did not differ.
  2. Practise the change: shoes ready, helmet rule checked, a smooth switch. Time two or three transitions in the last weeks.
  3. Run the first 3 to 5 minutes by feel, with short, quick steps. Stand tall, because the review notes that the trunk leans further forward after cycling.
  4. Drink and eat on the bike, not when the run begins. On long bricks it is the cheapest way to avoid a flat run.
  5. Judge the run by effort, not pace. The first kilometre often looks slow on your watch, and that is normal. Use easy running and zone 2 as your reference for easy.

How do brick workouts help in a fitness race?

A fitness race asks for a similar skill many times: running 1 km on legs that a station has just tired, eight times. A brick is the triathlon version, once. The idea carries over, but this is our reasoning and not a study of fitness racers.

Work out your finish time

Enter your swim, bike and run pace and your transition times to get a split for every leg and a finish time, with an optional cut-off check.

Use the triathlon calculator

Frequently asked questions

Sources

Published figures are quoted from these pages. Where datasets disagree we say so. Advice marked as our recommendation is not from a source.

HYROX® is a trademark of HYROX World GmbH; IRONMAN® and 70.3® are trademarks of World Triathlon Corporation. Tuffr is not affiliated with or endorsed by these organisers.

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