Can I Run My Target Time?

The time in your head is usually a round number. Sub-4. Sub-50. Sub-25. Nice and clean. Then you look at the week you actually ran: a 10K in the rain, a half that felt heavy, 35km because Thursday vanished into emails.

I have done this more times than I care to admit. Picked a time because it sounded like a proper runner. Hoped the long run would catch up. Sometimes it does. Sometimes kilometre 32 has other ideas.

This is a first go at asking the question without lying to myself. Four distances only — 5K, 10K, half, marathon. You put in what you have been running. It has a sniff at whether that time is in the building, or still living in a spreadsheet.

I am not a coach. This will not tell you what to do on Tuesday. It is just a slightly less wishful reading of the numbers. A good 5K does not get to quietly claim a marathon it has not trained for. I say that as someone who has tried.

What it is actually looking at

The races first. A recent half says more about a marathon than a 5K does. The other way round is also true. It translates those times across the distance — the usual formulas, with a second opinion so one of them cannot run off with the story — and then it looks at the week behind them.

Because a predicted 3:52 from a sharp 10K is a different animal if your longest run lately is 18km. Speed is one thing. Still being upright at 35km is another.

If you add a race date, it asks whether there is time to grow the mileage. You can add kilometres. You cannot invent a new 5K in three weeks. I have tried. It does not work.

Whatever you type stays on this page. Nothing gets sent anywhere. I would not want my embarrassing 10K living on a server either.

How to read it

LIKELY — the races and the week both say yes, or they will if you use the weeks you have for boring kilometres rather than heroics.

POSSIBLE — not fantasy. Often the speed is nearly there and the long run, or the weekly total, is the thing in the way. That was me, more than once, staring at a sub-4 that my 10K liked and my Sunday run did not.

STRETCH — you would need the block to go well and the day to go quietly. Not impossible. Not the default either.

UNLIKELY — the gap is large, or the date is soon, or both. Better to find that out on a Wednesday than at kilometre 32, bargaining with a gel.

The pace line is the bit I actually use. Target pace is just the time sliced into kilometres. Current estimated pace is what the numbers think you can hold today, once the week has had its say. The gap is the seconds per kilometre you are being asked to find. On tired legs, those seconds feel longer than they look.

What it will not do

It will not know about hills, heat, a cold, a course that keeps turning, or the fact you slept badly. It will not write you a plan. It assumes the times are recent and honest — not a downhill smash, and not a 10K you ran when you were a different person.

If it says POSSIBLE, skip the badge for a second. The sentence underneath is the useful part. That is the one to take into the week.

If the number in your head is a sub-25 5K, I wrote down what that actually asks of a week in What do you need for a sub-25 5K?