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Training glossary

Brick workout

Definition of Brick workout, why it matters for training, common mistakes, and practical ways to train it.

Updated Jul 26, 2026

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Definition

Brick workout

A brick workout pairs two disciplines back-to-back (commonly bike then run) to practice the transition and running on ‘bike legs’.

What a brick workout means

A brick workout combines two triathlon disciplines in sequence, most often cycling immediately followed by running. Its job is to rehearse the transition and answer one pacing, equipment or fueling question—not to simulate an entire race every week.

The first minutes of the run can feel unfamiliar because cycling changes the task immediately before running. Research on bike-to-run effects reports variable biomechanical and physiological responses, so no single brick format is required for every athlete.

Choose the brick by its question

QuestionUseful sessionKeep controlled
How should the opening run feel?ordinary ride + short easy runfirst 10 minutes
Does the fueling plan transfer?long ride + short race-specific runproduct and timing
Can transition setup be simpler?short bike + repeated transition practiceshoes, helmet, route
How does race effort combine?occasional specific bricktotal stress and recovery

A first brick

Ride at a familiar easy effort, prepare the transition before starting, then run 10–20 minutes conversationally. Record how long the transition took, how the first five minutes felt, and whether any pain or equipment issue changed movement.

Add duration or race specificity only after the simple version recovers normally. The IRONMAN 70.3 training hub can place bricks in the wider build, while the 70.3 fueling planner makes nutrition assumptions explicit.

Common mistakes

  • turning every brick into a race;
  • running hard because the first kilometre feels awkward;
  • introducing new shoes, fuel and intensity at the same time;
  • extending the run when bike fatigue has already changed form;
  • comparing a short transition split with an open running result.

Stop for chest pain, faintness, severe breathing difficulty, acute injury or pain that changes movement. A brick is training evidence, not a readiness diagnosis, and this page is not medical advice.

Why it matters

What it changes in training

  • It reduces the shock of transitioning to the run under fatigue.
  • It’s a safe way to rehearse fueling and pacing under realistic conditions.
  • It builds confidence for race-day execution.

Common mistakes

Common mistakes

  • Making every brick a hard race simulation.
  • Skipping fueling practice and then blaming fitness on race day.
  • Running too fast off the bike early and blowing up later.

Example

A simple way to think about it

A simple brick: 60–90 min bike easy-to-steady + 15–25 min run easy. You’re rehearsing, not racing.

How to train it

Practical workouts

  • Start with short easy bricks, then extend duration gradually.
  • Practice a simple fueling plan on the bike so the run starts stable.
  • Use effort cues: the first 10 minutes of the run should feel controlled.

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FAQs

What is a brick workout?

A brick combines two triathlon disciplines in sequence, usually a bike ride followed immediately by a run, to rehearse transition and combined-race demands.

How long should a first bike-run brick be?

Keep the ride familiar and the run short enough to remain conversational, often 10–20 minutes. The exact duration depends on recent training and recovery.

Should every brick be hard?

No. Most bricks can answer a pacing, transition or fueling question at controlled effort. Full race-specific sessions are occasional and need more recovery.

Why do my legs feel strange off the bike?

Cycling changes the task immediately before running, and responses vary. Start the run conservatively and use repeatable practice rather than forcing open-run pace.

Keep going

Sources