Every Brick Session, and What It Is For.

I asked an athlete what his brick session was for. He said it was to get used to running off the bike.

Fair enough. But he had been doing the same one for two years, a three hour ride followed by fifteen minutes of jogging, and he had got extremely good at running slowly on tired legs. On race day he still could not hold his target pace off the bike, because he had never once practised holding his target pace off the bike.

You do not get used to running off the bike. You get used to whatever you actually did off the bike.

Why the Legs Feel Wrong

Worth understanding before you decide which session to do, because it explains why the different versions exist.

Three things change at once. Cycling is a pushing action with a narrow range of motion and no impact. Running is elastic, wide range, and every stride is an impact. Switching from one to the other asks your neuromuscular system to change pattern immediately, and it is slow about it.

Then blood distribution. After hours on the bike a lot of your circulating volume is in the quads and the cycling musculature, and it takes several minutes to redistribute toward the running muscles.

And then cadence. Most people ride at eighty to ninety revolutions and run at around one hundred and seventy to one hundred and eighty steps. Your nervous system has been running one rhythm for hours and now has to double it.

That is why the first ten minutes feel like somebody else's legs. It resolves. The training question is what you want to be capable of while it resolves.

The Five, and What Each Trains

The starter brick. Forty minutes on the bike, ten minutes running, easy throughout. Its only job is to make the sensation familiar so it is not a shock. This is where beginners start and it does exactly what it says.

The cadence brick. Ride the last ten minutes at high cadence, above one hundred, low resistance, then run. You are pre-loading the rhythm change so the legs arrive already turning over. I use this with athletes whose first kilometre is always ugly, and it works quickly.

The race pace brick. This is the one people avoid and the one that matters most. Ride at your intended race power, for a meaningful chunk of time, then run at your intended race pace. Not jog. Race pace. This is the only session that answers the actual race day question, which is whether your bike plan leaves you able to run your run plan.

The threshold brick. Short, hard bike effort into a hard run. Twenty minutes at threshold, ten minutes running strong. This is a fitness session that happens to be a brick, and it builds the ability to keep pushing when the legs are already loaded.

And the long durability brick. A long ride into a moderate run of thirty to forty five minutes, for half and full distance athletes. This one is about fuelling and fatigue resistance more than mechanics, and it is where you find out whether your nutrition plan survives contact with the run.

The Mistake Almost Everyone Makes

Doing the long one every time.

It is the most obviously race-like, it feels the most virtuous, and it costs the most to recover from. So athletes do it fortnightly, recover from it for four days, and never do the sessions that would actually change anything.

A twenty minute run at race pace off a ninety minute ride teaches you more than a fifteen minute jog off a four hour ride, and costs a fraction as much.

The other mistake is treating the run as an afterthought. If the run portion is always so short and so slow that it cannot go badly, you never learn anything from it. The run is the part you are testing.

How I Programme Them

One brick a week in the build phase, rotating through the types rather than repeating one. Cadence brick, race pace brick, threshold brick, then the long one, then back round.

The race pace brick goes in every fortnight without fail in the eight weeks before an A race, because that is the session that either validates your race plan or tells you it is fiction. I would rather find out in October than at kilometre three.

And I put them on days the readiness supports. A brick is a hard session dressed up as two easy ones, and athletes routinely underestimate what it costs them.

Do the Transition Too

If you are doing a brick anyway, spend the ninety seconds doing the transition properly. Bike racked, helmet off, shoes changed, running. It costs you nothing and it means transition gets rehearsed thirty times a season instead of never.

Most athletes ride into the driveway, take five minutes to sort themselves out, and then start running. That is not a brick, that is two sessions with a gap.

The Bottom Line

Pick the brick that trains the thing you actually need. If your first kilometre is ugly, do cadence bricks. If your race pace collapses off the bike, do race pace bricks, at race pace, and find out now.

And stop doing the four hour ride with a jog on the end every fortnight. It is the most expensive session on the list and it is answering a question you already know the answer to.