Triathlon
What is a brick workout?
The back-to-back session that teaches your legs to run off the bike: why it matters, and example workouts to try.
A brick workout is two triathlon disciplines done back-to-back with little or no rest, usually a bike ride straight into a run. The point is to rehearse the exact moment a triathlon is won or lost: the transition from one sport to the next, when your body has to adapt on the move.
The name comes from how your legs feel on that first run off the bike: heavy, stiff, and awkward, as if they were made of brick. Bricks train that feeling away so it does not surprise you on race day.
Why brick workouts matter
Cycling and running use your muscles differently. When you step off the bike and start running, blood is still pooled in your cycling muscles, your stride feels clumsy, and your pace judgment is off. In a race, those first minutes off the bike are where many athletes lose time or blow up.
Brick training produces two adaptations. Physically, your body gets better at redistributing blood flow and settling into running mechanics quickly. Mentally, you learn what "heavy legs" feels like and how fast the sensation fades, so instead of panicking, you settle into your pace and let it come back.
Example brick sessions
Beginner: short transition rehearsal
40–60 minutes of easy-to-moderate cycling, then transition as quickly as you can into a 10-minute easy run. The run is short on purpose: you are teaching the switch, not racing.
Intermediate: race-pace off the bike
60–75 minutes of riding with the final 15 minutes at your target race effort, straight into a 20–25 minute run that starts at race pace. This rehearses holding pace when your legs feel their worst.
Advanced: multi-brick intervals
Alternate 3 rounds of roughly 15 minutes hard on the bike with 5–10 minutes of running at race pace. Repeated transitions sharpen both the physical switch and your pacing discipline under fatigue.
A swim-to-bike brick is also useful for open-water races, but the bike-to-run brick is the classic because that transition hurts the most.
Bricks only work when they land in the right week of your build. See how Gritup schedules them inside a full training block with Gritup for triathlon.
Frequently asked
What is a brick workout?
A brick workout is two triathlon disciplines performed back-to-back with little or no rest between them, most often a bike ride immediately followed by a run. The goal is to train your body for the specific feeling of switching from one sport to the next in a race.
Why is it called a brick?
The name most commonly refers to how your legs feel running straight off the bike: heavy and stiff, like they are made of bricks. Some also say it stands for 'Bike-Run Interval Conditioning.' Either way, it describes the same back-to-back session.
How often should I do brick workouts?
For most age-group triathletes, once a week or once every two weeks is plenty in the build phase before a race. Bricks are demanding, so you do not need many. A handful of well-timed sessions teaches the transition without adding excessive fatigue.
How long should the run be after the bike?
Start short. Even a 10 to 15 minute run off the bike teaches the transition feeling. As the race approaches you can extend the run to rehearse race-day pacing, but the first few minutes off the bike matter most because that is when your legs feel worst.
Are brick workouts only for triathletes?
Mostly, yes. Bricks exist to prepare you for the specific demand of racing multiple disciplines in sequence, so they are a triathlon and duathlon staple. Single-sport runners and cyclists rarely need them.
Train the transition
Bricks win races. A plan puts them in the right week.
Gritup builds an adaptive triathlon plan across swim, bike, and run, with brick sessions scheduled at the right time so race day feels rehearsed, not shocking.