A brick workout stacks two endurance disciplines back to back with little or no rest between them, most often a bike ride followed immediately by a run. Triathletes rely on brick training to rehearse race day transitions, condition the nervous system for the odd sensation of running off the bike, and turn two short sessions into one efficient block of work.
This guide explains what brick workouts are, where the name comes from, what happens inside your body during the bike to run transition, and how to start your first brick session safely at home.
Table of Contents
- What Is a Brick Workout?
- Where Does the Name Brick Workout Come From?
- What Are the Main Types of Brick Workouts?
- How Does the Bike-to-Run Transition Affect Your Body?
- What Are the Benefits of Brick Training?
- How Should Beginners Structure a First Brick Session?
- How Often Should You Do Brick Workouts?
- What Are Common Brick Workout Mistakes to Avoid?
Key Takeaways
- Definition: A brick workout is any session that stacks two disciplines, usually bike then run, with minimal rest between them.
- Main purpose: Bricks train your body and mind to handle the awkward transition from non-weight bearing cycling to weight bearing running.
- Time efficiency: A 10 to 30 minute run tacked onto a ride delivers more value than the same run done fresh on another day.
- Programming: One short brick per week is enough for most age group triathletes, with intensity added only after the legs feel controlled.
- Home friendly: An indoor trainer next to a treadmill, or a stationary bike paired with a quick outdoor run, makes bricks easy to do at home.
What Is a Brick Workout?
A brick workout is a single training session in which two endurance sports are performed back to back with no significant rest between them. The most common format is a bike ride followed immediately by a run, often called a run off the bike, because that transition is the hardest one to master on race day.
Endurance athletes use bricks to rehearse the specific demands of a triathlon, duathlon, or any event that asks the body to switch sports under fatigue. Pair a ride with our circuit training workouts for a balanced weekly schedule.
Where Does the Name Brick Workout Come From?
No single origin is official, and asking ten triathletes will usually return ten different answers. The three most common explanations all describe the same training concept, so the exact origin matters less than understanding the session itself.
- Heavy legs: Many athletes say their legs feel like bricks during the first minutes of running off the bike.
- Foundation: Others say each session lays another brick in a strong triathlon foundation.
- Acronym: A popular reading treats brick as a short form of bike and run in combination.
The term now covers any back to back discipline pairing, including swim to bike and run to bike to run, not only the bike run version.
What Are the Main Types of Brick Workouts?
Several brick formats exist, and each trains a different transition or race scenario. The right choice depends on your race distance, weaknesses, and available equipment.
- Bike to run: The classic brick, used by almost every triathlete to rehearse the T2 transition.
- Swim to bike: Common for draft legal and short course racers who need to settle into race pace cycling right after a hard swim.
- Run to bike to run: A duathlon staple that loads the run twice and is brutal on the calves.
- Soft versus hard brick: A soft brick allows a relaxed transition, while a hard brick simulates race day pace and gear changes.
For home training, the bike to run version is the simplest to set up, especially if you keep functional training equipment nearby for transition practice.
How Does the Bike-to-Run Transition Affect Your Body?
Running immediately after cycling changes the way your muscles fire, how much oxygen they can use, and how your stride looks. Three peer reviewed studies of trained triathletes have quantified these effects and explain why the first kilometer of a triathlon run feels so awkward.
- Lower mechanical efficiency: A study of collegiate triathletes found that a 40 km cycling bout lowered running mechanical efficiency and modestly raised blood lactate and respiratory exchange ratio compared with a non cycling run.[2]
- Shorter stride: A study of ten trained triathletes reported that prior cycling cut running distance, shortened stride length by about 0.1 m, and raised muscle oxygen saturation despite maximal effort, while cadence and heart rate were largely unchanged.[1]
- Longer transient phase: A study of 22 well-trained triathletes measured the distance needed to overcome the uncoordinated T2 sensation, about 679 m after cycling versus about 450 m after an energetically matched run preload and about 294 m in an isolated run.[3]
The takeaway is that brick training exists because the bike to run switch is a real physiological and biomechanical event, not just a feeling. Repeated exposure is the most reliable way to shorten that awkward transient phase.
What Are the Benefits of Brick Training?
Brick workouts are one of the best return on time investments in endurance training because they stack two stimuli into one block of fatigue. The benefits extend well beyond simply feeling less jelly legged on race day.
- Neuromuscular adaptation: Bricks teach your brain to switch muscle recruitment patterns from the circular pedal stroke to the upright run gait more smoothly.
- Transition rehearsal: Practicing the bike to run switch under fatigue turns T2 into an automatic routine on race day rather than a chaotic moment.
- Nutrition and pacing practice: Bricks are the best time to test your fueling, hydration, and heart rate targets off the bike.
- Time efficiency: A short run tacked onto a ride adds meaningful stimulus without doubling your weekly session count.
- Mental toughness: Experiencing the heavy legs sensation in training reduces the mental shock when it happens in a race.
For readers focused on general conditioning rather than triathlon, brick principles also apply to strength endurance blocks. See our metcon workouts guide and the popular Tabata workout structure for related formats.
How Should Beginners Structure a First Brick Session?
Beginners should keep the first brick short, easy, and focused on form rather than pace. The goal is to teach the nervous system the bike to run switch, not to set a personal best on either segment.
- Step 1: Ride 20 minutes at conversation pace on an indoor trainer or stationary bike.
- Step 2: Dismount, change shoes, and start the run within 60 seconds to mimic race day.
- Step 3: Run 10 minutes at a relaxed pace, letting the legs find their rhythm for the first 2 to 3 minutes.
- Step 4: Cool down, stretch the calves and hip flexors, and note how the legs felt during the first kilometer.
The following video walks through how an experienced coach builds brick sessions into a simple half ironman training week.
At home, you can pair any stationary bike with a quick treadmill or outdoor run. Add leg training for women or general home gym strength training on non brick days to build the durability your run legs need.
How Often Should You Do Brick Workouts?
One brick session per week is enough for most age group triathletes, with the bulk of bricks stacked into the final six weeks before a key race. Elite athletes may add a second lighter brick for pure transition rehearsal, but beginners should resist the urge to copy that volume.
"On the hard days, triathletes do a brick, a bike followed by a run, and they can vary which part is the intense segment from day to day."
Joe Friel, Endurance Sports Coach and author of The Triathlete's Training Bible, TrainingPeaks
His point is that the bike and the run can be swapped in priority depending on the day, so the brick stays adaptable rather than rigid. Pair this approach with one of our bodyweight CrossFit workouts for conditioning variety.
What Are Common Brick Workout Mistakes to Avoid?
Even experienced athletes make predictable mistakes with brick training that blunt the benefits or add injury risk. Avoiding these pitfalls keeps the session effective and sustainable.
- Going too long: A 90 minute ride plus a 90 minute run is two full workouts stacked, not a brick, and the fatigue will set back your week.
- Pacing too hard: Almost every athlete runs too fast in the first mile off the bike. Force a negative split instead.
- Skipping transition practice: A relaxed soft brick still has value, but if you never rehearse a quick T2 you will lose time on race day.
- Ignoring nutrition: Bricks are the right moment to test your fueling plan, since off the bike digestion feels different.
- Adding bricks too early: Build an aerobic base first, then layer bricks in the build phase, not the other way around.
If you also lift, be careful with bricks the day after heavy squats or deadlifts, since pre-fatigued legs distort the run adaptation. The RitFit 15kg Olympic Training Barbell is a fine strength tool to keep brick days and heavy days separate.
FAQs About Brick Workouts
What is a brick workout?
A brick workout is a training session that stacks two endurance disciplines back to back with little or no rest in between. The most common version is a bike ride followed immediately by a run, also called a run off the bike. Athletes also use swim to bike or run to bike to run versions to rehearse race day transitions.
Why is it called a brick workout?
Triathletes disagree on the origin, so three explanations coexist. Some say your legs feel like bricks when you start running off the bike, others that each session lays another brick in your fitness foundation, and others that brick stands for bike and run in combination. None is official, so use whichever helps you remember the concept.
How long should a brick run be?
Most brick runs are intentionally short, often 10 to 30 minutes, because the goal is transition adaptation rather than run endurance. Beginners can benefit from as little as 10 minutes off the bike. Long runs belong on their own day, and stacking two full workouts usually creates too much fatigue for the rest of your week.
How often should I do a brick workout?
Most coaches suggest one brick session per week during the build phase, especially in the final six weeks before a race. Elite athletes may add a second lighter brick for transition rehearsal. Beginners should start with one short brick every 7 to 10 days and increase only when the legs feel controlled off the bike.
Can I do a brick workout on a home gym setup?
Yes, a stationary bike or indoor trainer next to a treadmill works very well for bricks because the transition is fast and weatherproof. You can also pair a bike trainer with an outdoor run, or use functional training equipment for strength focused bricks. Keep your run shoes and nutrition within arm reach to mimic race day.
Does a brick workout burn more calories than separate sessions?
A brick tends to feel harder because you carry fatigue from the first discipline into the second, which can raise perceived effort and heart rate. Calorie burn depends on duration and intensity, not session order alone. The main value of a brick is transition practice and time efficiency, not a guaranteed higher calorie total.
Should beginners do brick workouts?
Yes, beginners benefit from short bricks because the bike to run sensation is the part most likely to derail a first triathlon. Start with a 20 minute easy ride and a 10 minute easy run, focus on smooth form, and add intensity only after the transition feels familiar. A coach or structured plan helps you progress safely.
Conclusion
Brick workouts are the simplest tool endurance athletes have for rehearsing the messy, fatiguing transitions that define a triathlon or duathlon. One short, well paced brick per week, focused on form rather than heroics, is enough to shorten the awkward T2 phase and build genuine race day confidence.
Start with a 20 minute ride and a 10 minute run, keep the gear staged, and add intensity only after the legs feel controlled. For more on mixed-modality training at home, browse our military workout and barre workout guides.
Disclaimer
This article is for general information on training concepts and does not replace personalized coaching or medical advice. Always consult a qualified coach or healthcare professional before starting a new training program, especially if you have a heart condition, joint issue, or are returning from injury.
References
1. Olcina G, Perez-Sousa MÁ, Escobar-Alvarez JA, Timón R. Effects of Cycling on Subsequent Running Performance, Stride Length, and Muscle Oxygen Saturation in Triathletes. Sports (Basel, Switzerland). 2019;7(5). https://pmc.ncbi.nlm.nih.gov/articles/PMC6572577/
2. Stewart JA, Merritt EK, Lidstone DE, McBride JM, Zwetsloot KA. Prolonged cycling lowers subsequent running mechanical efficiency in collegiate triathletes. BMC sports science, medicine & rehabilitation. 2022;14(1):149. https://pmc.ncbi.nlm.nih.gov/articles/PMC9344700/
3. Weich C, Barth V, Killer N, Vleck V, Erich J, Treiber T. Discovering the sluggishness of triathlon running - using the attractor method to quantify the impact of the bike-run transition. Frontiers in sports and active living. 2022;4:1065741. https://pmc.ncbi.nlm.nih.gov/articles/PMC9802668/
