If you’re training for a Sprint or Olympic-distance triathlon, you’ve probably heard that you need to include brick sessions.
Bike. Quick transition. Run.
But how important are they really?
Do you need to run after every bike ride?
Should your brick run be the full 5km you’ll race in a Sprint triathlon—or even 10km if you’re preparing for an Olympic-distance event?
And does running on tired legs automatically make it a better workout?
No.
Brick sessions are valuable for Sprint and Olympic-distance triathletes, but you probably don’t need as many—or as much running off the bike—as you might think.
The key isn’t simply doing bricks.
It’s understanding why you’re doing them.
What Is a Brick Session?
A brick session combines two disciplines back-to-back with relatively little time between them.
Although you can complete combinations such as:
Swim → Bike
the most common brick is:
Bike → Run
You finish your ride, make a reasonably quick transition, put on your running shoes and start running.
That sounds simple enough.
Until you actually try it.
Your legs can suddenly feel heavy and awkward. Your normal running stride might seem to have disappeared, and the pace you’re running can feel completely different from what you expect.
Fortunately, that feeling usually settles.
More importantly, you can train your body to become familiar with the transition.
I’ve previously gone into considerably more detail about what happens when your body moves between disciplines and why practising that transition can help.
Why Are Bricks Useful for Sprint and Olympic Triathletes?
The bike-to-run transition matters regardless of which triathlon distance you’re racing.
But there’s an interesting difference with shorter events.
In a Sprint triathlon, you’ve only got around 5km of running.
In an Olympic-distance triathlon, you’ve got around 10km.
You don’t necessarily have several kilometres available to settle yourself down, find your running legs and eventually establish your race rhythm.
The sooner you can transition efficiently and begin running appropriately, the better.
That’s one reason brick training can be particularly useful for shorter-course athletes.
You aren’t simply developing fitness.
You’re practising the ability to access your running fitness quickly after cycling.
What Are You Actually Training?
One of the biggest misconceptions about brick sessions is that their purpose is to make you tougher at running with tired legs.
That’s part of the experience, but it’s not the main objective.
A well-designed brick can help you practise several different aspects of racing.
The Bike-to-Run Transition
Cycling and running place different demands on your body.
You go from sitting on the bike and producing repeated pedal strokes to suddenly supporting your bodyweight and running.
Your posture changes.
Your movement pattern changes.
The muscular demands change.
And your body needs to adjust.
That’s part of the reason those first few hundred metres can feel so strange.
The good news is that repeated exposure makes the experience more familiar. That’s something I explored in much more detail in Why Are Bricks Important?, including how the demands shift as you move from cycling into running.
👉 Read: Why Are Bricks Important?
The aim isn’t necessarily to eliminate every strange sensation.
It’s to make sure that when you experience it on race day, your response is:
“I know what this feels like.”
rather than:
“What on earth has happened to my legs?”
Your Brick Run Doesn’t Need to Be Long
This is probably the most important practical point.
You don’t necessarily need to complete a long run after cycling to gain the benefit of a brick session.
Sometimes 10–20 minutes is plenty.
Think about what you’re trying to achieve.
You want to experience the transition.
You want to establish your running mechanics.
You want to find your rhythm.
You want to practise controlling your opening pace.
Once you’ve achieved those things, adding another 30 or 40 minutes of running doesn’t automatically make the workout better.
It certainly makes it longer.
It also increases the training load and recovery requirement.
That doesn’t mean longer brick runs never have a place. As your training progresses, there may be occasions when a more substantial or race-specific brick is appropriate.
But don’t assume:
Longer brick = better brick.
The purpose of the workout should determine its duration.
The Biggest Brick Mistake: Running Too Fast
You’ve finished the bike.
You’ve made your way through transition.
Your running shoes are on.
You’re feeling excited.
And away you go.
Far too quickly.
Running pace can feel surprisingly strange immediately after cycling.
Your legs have been turning over repeatedly on the bike, and when you begin running your perception of speed may not be particularly accurate.
Your planned pace can feel too slow.
So you speed up.
For a Sprint triathlon, that mistake can become expensive very quickly.
You don’t have much time to recover from an opening kilometre that’s considerably faster than you can sustain.
For an Olympic-distance race, you’ve still got most of a 10km run ahead of you.
Brick training gives you the opportunity to practise something extremely valuable:
restraint.
For many introductory bricks, I want the athlete to settle into a controlled Level II effort rather than immediately trying to prove how fast they can run off the bike.
Later, appropriately designed sessions can introduce more race-specific intensity.
But the intensity should always have a purpose.
Your Run Starts Before You Leave T2
There’s another lesson brick sessions can teach particularly well:
The quality of your run is influenced by what you did on the bike.
You can have excellent running fitness and still produce a disappointing run split if you’ve over-ridden the bike.
That’s why a good brick isn’t just an opportunity to assess your running.
It’s an opportunity to examine the relationship between the two disciplines.
How does your running feel after an appropriately paced bike?
Can you find your rhythm quickly?
Can you settle into the intended running intensity?
What happens when you push the bike harder?
These are useful lessons to learn during training rather than discovering them for the first time on race day.
Think About the Final Minutes of the Bike
Your brick doesn’t have to begin when you put your running shoes on.
You can also practise how you approach T2.
In my earlier article, Why Are Bricks Important?, I discuss reducing cycling intensity during the final few minutes of the ride rather than charging all the way into transition. The idea is to make the change from cycling to running less abrupt.
That doesn’t mean freewheeling through the final kilometres of your race.
It means learning how your body responds to different approaches.
A training brick is the perfect environment to experiment.
👉 Read more about preparing your legs for the bike-to-run transition
Coach Ray’s Tip: Think About Your Cadence
Another useful detail is your cycling cadence as you approach transition.
I generally encourage an efficient cycling cadence in the region of 90–100rpm, and this can be particularly useful approaching a bike-to-run transition.
If you’re grinding a large gear at 70rpm immediately before T2, you’re asking your legs to suddenly change from relatively slow, forceful pedal strokes into the quicker turnover required for running.
Instead, approaching transition with your normal efficient cadence can help make that change feel smoother.
This is something I also discussed in Why Are Bricks Important?, where I recommended keeping cadence relatively high approaching transition rather than grinding a large gear.
Practise Your Transition Too
A brick session doesn’t only train what happens to your legs.
It gives you an opportunity to practise T2 itself.
That can include:
- getting off your bike efficiently;
- putting your bike where it needs to go;
- removing your helmet;
- changing into your running shoes;
- putting on your race belt; and
- heading out onto the run.
For Sprint and Olympic-distance racing, those little efficiencies can matter.
But I’m not suggesting you become obsessed with saving fractions of a second.
The bigger objective is to make transition automatic.
You don’t want to arrive at T2 on race day and suddenly wonder where your shoes are, which way your race belt goes or what you’re supposed to do next.
Practise it until it becomes familiar.
Don’t Turn Every Bike Ride Into a Brick
If bricks are useful, surely doing more of them is better?
Not necessarily.
Your training programme still needs to develop you as a:
swimmer;
cyclist;
and
runner.
Some of your running sessions are best completed when you’re fresh enough to achieve the purpose of that workout.
Adding a run after every bike ride increases your running frequency, impact and total training load.
That needs to be accounted for.
So don’t add a brick simply because you’ve finished a bike session and you’ve got another pair of shoes sitting beside the trainer.
Ask:
What am I trying to achieve?
If there isn’t a good answer, you probably don’t need the additional run.
The same principle applies to longer-course training. In my Ironman 70.3 brick guide, I explain why even athletes preparing to run a half marathon after 90km of cycling don’t need every ride to become a brick or every brick run to be long.
👉 What Is a Brick Session and Do You Really Need Them? — Ironman 70.3 Guide
Don’t Race Every Brick
There’s something very tempting about finishing a ride and then seeing how fast you can run.
You might even think:
My Sprint triathlon finishes with a 5km run, so why don’t I ride hard and then see how fast I can run 5km?
Occasionally, a demanding race-specific session may have an appropriate place within your programme.
But you don’t need to conduct a fitness test every time you complete a brick.
Sometimes the correct brick run is deliberately easy.
Sometimes the objective is simply to spend 10 minutes at Level II finding your running rhythm.
Sometimes the session might progress through different intensities.
Later, you might include work that reflects the demands of your upcoming race.
The correct intensity is determined by why the workout is in your programme.
Don’t measure the quality of a brick by how exhausted you are afterwards.
Measure it by how well you achieved its purpose.
What About Swim-to-Bike Bricks?
Bike-to-run bricks get most of the attention, but remember that triathlon has two transitions.
Occasionally practising:
Swim → Bike
can also be worthwhile.
This is particularly useful when you can replicate aspects of race day.
You might practise getting out of your wetsuit, organising your equipment, getting onto the bike and settling into your planned cycling intensity.
There’s also the simple experience of changing from a horizontal swimming position to being upright and beginning to cycle.
You don’t necessarily need to practise swim-to-bike bricks as frequently as bike-to-run.
But it can be useful to ensure the first time you experience the complete process isn’t race morning.
Use Bricks to Practise Race Day
As your event approaches, selected brick sessions can become more specific.
Now you’re not just learning what running after cycling feels like.
You’re rehearsing your event.
Depending on the purpose of the workout, you can practise:
- bike pacing;
- approaching T2;
- transition;
- opening run pace;
- fuelling and hydration;
- race equipment; and
- maintaining good technique as fatigue develops.
This is where brick training becomes particularly valuable.
You’re learning how to connect the fitness you’ve developed in each individual discipline.
You’re no longer just building your swim fitness, bike fitness and run fitness.
You’re learning how to race a triathlon.
When Should You Introduce Brick Sessions?
If you’re new to triathlon, you don’t need to make bricks the centre of your training from day one.
First, establish the foundations.
Become comfortable swimming regularly.
Develop your cycling fitness.
Build your running durability.
Establish consistency.
Then introduce bricks progressively.
Your first brick might be incredibly simple:
Normal bike session → 10 minutes Level II running
That’s enough to begin learning how the transition feels.
As you develop, your brick sessions can progress.
Some can become longer.
Some can become more intense.
Some can become increasingly race-specific.
But that progression should happen because your training is developing—not because you feel every brick needs to be harder than the previous one.
So, Do You Really Need Brick Sessions?
Strictly speaking, you could become extremely fit without doing a brick.
Cycling will develop your cycling fitness.
Running will develop your running fitness.
But there’s one rather important problem:
You’re not entering a bike race followed several hours later by a running race.
You’re entering a triathlon.
You need to get off the bike and start running immediately.
For a Sprint-distance athlete, you then have 5km to run.
For an Olympic-distance athlete, 10km.
That makes the ability to transition efficiently, control your opening effort and find your running rhythm a skill worth practising.
So yes, I recommend including brick sessions.
Just don’t confuse important with constant.
The Bottom Line
Brick sessions have an important place in Sprint and Olympic-distance triathlon training.
But you don’t need to run after every ride.
You don’t need every brick run to be long.
And you certainly don’t need every brick to leave you exhausted.
Start with short, controlled bike-to-run transitions.
Learn how your body responds.
Practise your pacing.
Experiment with how you approach T2.
Keep your cycling cadence efficient.
Practise your transition routine.
Then progressively make selected bricks more specific to the demands of your event.
Because triathlon isn’t simply about becoming a good swimmer, cyclist and runner.
It’s about learning how to put all three together.
🏊🚴🏃 Put It All Together With Triathlon Mastery
Knowing that you should include brick sessions is the easy part.
The harder questions are:
When should you do them?
How long should they be?
How hard should you run?
How do they fit around your swimming, cycling, running and recovery?
That’s why a training programme matters.
Triathlon Mastery is designed to give you a structured, progressive approach to preparing for your Sprint or Olympic-distance triathlon, rather than leaving you to collect individual workouts and hope they fit together.
You’ll build your fitness progressively, develop across all three disciplines and introduce race-specific training when it has a reason to be there.
Because the goal isn’t to do as much training as possible.
It’s to do the right training at the right time for the right reason.
Train with purpose. Build consistently. Arrive ready to race.