What a race sheet is
In a backyard the loop starts every hour, on the hour, until only one runner is left standing. That turns the race into a string of small, repeated decisions, each one made with a little less clarity: what you eat on loop 14, whether you change your shirt before dark, when it’s time to check your feet. The sheet exists so those decisions are made before you start, while you can still think straight.
Almost everyone does it in a spreadsheet. What changes here is that the skeleton – the time of every loop, cumulative kilometres, where the marathon falls, where night comes in – builds itself, and anything repetitive is written once.
Rules instead of twenty-four lines
A rule is something that repeats every so many loops, like ‘every 3 loops, a gel’. You write it once and the tool puts it into every loop it applies to. If you change the target or the start time, it rearranges itself.
If two rules land on the same loop and in the same column, they add up and both appear. With ‘every 3 loops, a gel’ and ‘every 6 loops, broth’, loop 6 gets the gel and the broth.
The ‘Replaces’ box
It’s the exception to that adding up. A rule ticked this way erases what earlier rules wrote in that same cell and leaves only its own.
You can see it in the rules that come preset. One puts ‘500 ml water’ on every loop; another puts ‘500 ml + salt’ every four, and it’s ticked. That’s why on loop 4 the cell says only ‘500 ml + salt’: if it weren’t ticked it would say ‘500 ml water · 500 ml + salt’, which reads like two bottles when it’s really the same one, with salt.
It only affects its own column and the loops it applies to: the rest of the sheet stays the same. And it only erases what comes from the rules above it in the list; the ones you add below add up again.
When should you tick it? When the new thing is the same thing, changed, like the same bottle now with salt. If they are two different things and you need to do both, leave it unticked.
How we work out sunrise and sunset
Night is what really splits a backyard in two: it changes your kit, how quickly you get through the aid station and what you can manage to eat. That’s why the plan prints in day and night blocks, and the first night loop carries the exact time the sun sets.
It doesn’t come from any table or any weather lookup: it’s calculated with the solar equations published by NOAA, the same ones almanacs use. With the date of your race and the position of the town we get the Sun’s height hour by hour, and from that the moment it crosses the horizon. It takes into account that you see the Sun rise a little before it has actually come up, because the atmosphere bends the light.
It depends on the date of the race, not on when you look at the page: the same race always gives the same times. And if your backyard spans several days, each day gets its own: over a weekend sunset moves a few minutes from one day to the next.
If you choose a race from the calendar, we work it out for its town, and the sheet says which. If you type it in by hand we’re left with the capital of your province, which is the most precise point we can give without making it up; the difference is two or three minutes, and with starts every hour on the hour it doesn’t move a single row. If your race is outside Spain or you can’t find your province in the list, enter both times yourself and the sheet splits all the same.
A warning you’ll be grateful for during the race: the time we give is sunset, when the Sun goes down, and that isn’t the same as being left in the dark. After it there’s a good half hour of twilight when you can run perfectly well without a head torch, and in the morning it gets light about as long before sunrise. The reverse happens too: down in a ravine or in a pine wood it gets dark well before the sky does. The sheet gives you the reference; you decide on the head torch by looking at the terrain.
What to print and how to carry it
A4 portrait, with the column header repeated on every sheet and a box per loop to tick off. The preview above is the document: count the sheets before you hit print, and if there’s one more than you want, lower the blank loops. It’s designed to be read in black and white on a bad printer: no information depends on colour. Carry it in a plastic sleeve with a pen that writes when wet, and leave another copy on the table for whoever is crewing for you.