Brick session

A brick session is a bike ride followed straight away by a run. Plan one that fits your evening.

Your details

3 x (30 min bike + 10 min run)

2 hr 10 min

session time

Total bike1 hr 30 min, about 42.0 km (105% of a standard (Olympic) bike)
Total run30 min, about 5.1 km (51% of a standard (Olympic) run)
Transitions practised5
Run share25%
Run pace off the bike5:47 to 6:03 a km, 5 to 10% slower than your fresh 5:30
Your standard (Olympic) bike and run at these speeds2:24:50 (bike 1:25:43, run 59:08), so this session is 90% of that time
Fuelabout 65 to 130 g of carbohydrate over the session (30 to 60 g an hour), a good rehearsal for race day

The first few minutes off the bike feel odd for everyone. Start at the slow end of your off the bike pace, focus on quick light steps, and let the legs come back.

Chest pain, feeling faint or unusual breathlessness: stop, and call 999 if it does not pass.

The working

3 rounds of 30 minutes bike, 10 minutes run

That is 90 minutes on the bike and 30 running, with 5 transitions at 2 minutes each: 2 hr 10 min. Running is a quarter of the session.

At 28 km/h the 90 minutes ride about 42 km, slightly more than a standard distance bike leg (40 km). Off the bike, runs usually come in 5 to 10% slower than fresh at the same effort, so a fresh 5:30 a km becomes 5:47 to 6:03, and the 30 minutes cover about 5.1 km, half a standard distance run. Brick runs are usually kept short, with the long run as its own session.

Brick ideas

Pick one

Session	Good for
Long ride, 15 minute run	getting used to the feeling
3 x short bike and run	transition practice
Turbo plus treadmill	winter evenings
Race pace blocks	final weeks before a race

Race time and fuel

How the session compares

With your bike speed and fresh run pace, we also work out the race's own bike and run at those speeds: a standard distance 40 km at 28 km/h is 1:25:43, and 10 km at 5:47 to 6:03 a km is about 59:08, so 2:24:50 in all, and the 2 hr 10 min session is 90% of it. Sessions over 90 minutes come with a fuel row: 30 to 60 g of carbohydrate an hour, the ACSM and sports dietitians' guide, which is 65 to 130 g for this session and a good chance to practise race day food.

Off the bike

What helps

Spin an easier gear for the last few minutes
Short quick steps for the first kilometre
Run tall and relax your shoulders
Let the pace come to you

Read with care

What this cannot tell you

FatigueBricks are tiring; do not stack them with hard days.
WeatherRunning in wet bike kit gets cold fast.
SetupLeave your bike somewhere safe while you run.

Questions

Common questions

What is a brick session?

A bike ride followed straight away by a run.

How often should I do bricks?

Once a week or fortnight in the build up is common.

Why do my legs feel heavy running off the bike?

The muscles are used to cycling. It improves with practice.

Sources

Last checked 21 October 2026. Spotted something wrong? Tell us and we will fix it.

Before you push on

New to exercise, or got a heart, lung or joint condition? Have a word with your GP or practice nurse first. Stop and get help if you feel chest pain, faintness or unusual breathlessness, and call 999 if it is severe.