You Missed a Run. Don’t Try to Make It Up.

It’s Wednesday evening. The plan said eight miles with four at threshold. Work overran, the childcare fell through, and by the time you got home it was dark and you were done.

So now you’re doing the thing every runner does: working out where to put it. Thursday’s an easy day, so maybe you shift Wednesday to Thursday and push everything back. Or you double up on Friday. Or you tack the threshold work onto Saturday’s long run and just get it done.

Don’t. Skip it and carry on with Thursday as written.

That advice sounds lazy. It isn’t. Trying to reclaim missed sessions is one of the most reliable ways runners injure themselves, and the anxiety driving it costs more than the run would ever have earned.

First, the Maths

A standard 18-week marathon plan contains somewhere between 80 and 110 individual runs. Missing one is roughly 1% of your training.

One per cent will not change your finish time. It will not undo your base. It will not be the reason a race goes badly.

Fitness is built from the accumulation of months of consistent work, not from any individual session. No single run in your plan is load-bearing. The plan is load-bearing.

This is worth internalising, because the real damage from a missed run is almost never physiological. It’s what you do next.

Why “Making It Up” Backfires

Every method of reclaiming a missed session creates a new problem.

Doubling up

Two workouts in a day, or hard sessions on back-to-back days, concentrates stress your plan had deliberately spread out. Training plans aren’t a list of boxes to tick; the spacing between sessions does as much work as the sessions themselves. Compress that spacing and you get the load without the adaptation — which is a fairly precise description of how injuries happen.

Shifting everything back a day

This feels tidy and rarely is. Your long run moves to Sunday, which pushes Monday’s rest day to Tuesday, and by Thursday you’ve either got two quality sessions bunched together or you’ve quietly lost a rest day. One day of slippage propagates through the whole week.

Bolting the workout onto another run

Adding threshold work to a long run turns two moderate sessions into one very hard one. Occasionally that’s a legitimate workout in its own right — but it isn’t the workout your plan called for, and you’re doing it on legs that weren’t prepared for it.

Adding mileage later in the week

Weekly mileage is a target, not a debt. Adding aimless miles on Friday to “hit 45” gives you fatigue without purpose. The number was a proxy for training stress, and you’ve met the proxy while missing the point.

What to Do Instead

The whole protocol fits in one line: skip the missed run and do the next session as written.

No compensation, no adjustment, no arithmetic. Thursday’s run is Thursday’s run regardless of what happened on Wednesday.

If you want the slightly more considered version:

1. Skip it. The session is gone. It isn’t recoverable and doesn’t need to be.
2. Take the next run as scheduled, at the scheduled effort.
3. Don’t add anything to the rest of the week to compensate.
4. Note why you missed it — one line is enough. This matters later.
5. Move on.

The One Exception: Swapping, Not Adding

There’s a single adjustment that’s usually safe, and it’s a swap rather than an addition.

If you miss a key session — a long run, or your main quality workout of the week — and the following day is an easy or rest day, you can swap them. Run the key session a day late and take the easy day where the key session was.

The rules:

• Swap, never stack. Total weekly load stays the same.
• Never end up with two hard sessions on consecutive days.
• Do it once. If you’re swapping every week, the plan doesn’t fit your life and needs changing properly.

And if the swap doesn’t work cleanly — if it forces two hard days together — skip it instead. A missed long run costs you less than a badly placed one.

If You Have to Choose, Protect These

Some weeks you’ll know in advance you can’t complete everything. Triage rather than improvise.

Protect first:

• The long run. The most important session in any endurance plan, and the hardest to substitute.
• Your main quality session. Threshold, marathon-pace work, or intervals depending on the block you’re in.

Drop first:

• A mid-week easy run. Easy mileage matters cumulatively, not individually. Losing one is genuinely inconsequential.
• A second quality session in a week that has two.
• Strides, drills, and add-ons. Useful, not essential.

If the week has fallen apart and you can only save one run, make it the long run.

Different Reasons, Different Responses

Life got in the way

Work, family, travel, a broken boiler. Skip it, move on, no adjustment. This is the standard case and the standard answer applies.

You’re ill

Don’t run through it, and don’t reclaim the sessions afterwards. Training while unwell extends the illness and produces no useful adaptation.

The rough guide most coaches use: symptoms above the neck — a mild head cold, a blocked nose — and easy running is usually fine if you feel up to it. Anything below the neck, a fever, or body aches, and you rest until it clears, then return gradually rather than jumping back to where you left off.

Being unwell isn’t a training failure. It’s a thing that happens.

Something hurts

This is the one case where missing a run is unambiguously right, and where the instinct to make it up later is most dangerous.

If a niggle made you stop, don’t treat it as a scheduling problem. Rest it, work out what’s going on, and get it looked at if it persists beyond a few days. The missed session is irrelevant next to the eight weeks an ignored injury can cost you.

You just didn’t want to

Occasionally this is laziness. Far more often — particularly deep into a block — it’s your body telling you something before your head has worked it out. Persistent reluctance to run is one of the earliest signs of accumulated fatigue.

Skip it without guilt. If it happens once, it’s a bad day. If it keeps happening, see below.

The “Never Miss Twice” Rule

This is the only rule you actually need.

Missing one run is nothing. Missing two in a row is the start of a pattern.

One missed session has no effect on your fitness and no effect on your habits. Two starts to erode the second one. Three and you’re negotiating with yourself every day about whether to run at all.

So the standard isn’t perfection — it’s that you don’t let one become two. Miss Wednesday, run Thursday. That’s the whole discipline.

It’s also a far kinder standard than the one most runners hold themselves to, and considerably more sustainable across a four-month build.

When Missed Runs Are Telling You Something

An occasional missed session is normal. A regular pattern is information.

If you’re missing multiple runs most weeks, the problem isn’t discipline. One of these is usually true:

• The plan doesn’t fit your life. A six-day plan is not a moral achievement. If four or five days is what you can genuinely sustain, run a plan built for four or five days. You’ll get fitter on a plan you complete than on a better plan you don’t.
• You’re doing too much. Persistent reluctance, heavy legs and disrupted sleep often show up as missed runs before they show up as anything else.
• The schedule is wrong for your week. If Wednesday is always the run you miss, Wednesday is the problem. Move your rest day rather than fighting the same battle every week.
• You’ve lost interest in the goal. Worth knowing, and worth acting on, rather than grinding through.

This is why noting the reason is useful. One missed run tells you nothing. Twelve missed runs with a reason attached to each tells you exactly what needs to change — and it’s usually not you trying harder.

Coming Back From a Longer Gap

Sometimes it’s not one run. Sometimes illness, injury or life takes out a week or more.

Up to a week: You’ve lost essentially nothing. Rejoin the plan where it currently is — not where you left off. Take the first two or three runs easy and you’ll be back in rhythm within days.

One to two weeks: Some sharpness has gone; your aerobic base hasn’t. Rejoin at the current week, but ease back into quality work — take the first hard session at slightly reduced volume.

Two to four weeks: Now you need to rebuild rather than resume. Spend a week or two on easy running before reintroducing intensity, then rejoin. Be honest about whether your goal time still stands.

Over a month: This is a different training block, not a continuation. Rebuild your base properly, and genuinely consider whether the goal race is still the right target. Deferring, dropping to a shorter distance, or running it as a fun race are all legitimate answers.

In every case, rejoin where the plan is, never where you left it. Trying to complete missed weeks is the same mistake as making up a missed run, only larger.

The Bigger Point

The reason this matters isn’t really about training load. It’s that runners who treat every missed session as a failure tend not to last.

Perfectionism about training is fragile. The moment a plan becomes something you either complete flawlessly or have “ruined,” a single bad week can take the whole thing down. The ability to absorb disruption without spiralling is worth far more over a running life than any individual workout.

The runners who improve year after year aren’t the ones who never miss a session. They’re the ones who miss one, shrug, and turn up the next day.

The Short Version

• Missing one run is about 1% of a marathon plan. It doesn’t matter.
• Skip it. Do the next session as written.
• Don’t double up, don’t shift everything back, don’t add mileage.
• Swapping a key session with the next easy day is fine. Stacking is not.
• If you can only save one run, save the long run.
• Never miss twice in a row.
• Rest for illness and pain without guilt, and without making it up afterwards.
• After a long gap, rejoin where the plan is, not where you left it.
• A pattern of missed runs is information about the plan, not a verdict on you.

Building toward a goal race? Track it in RunningLog — set your target, log your result, and keep the perspective that one missed Wednesday never mattered.

What’s your rule for missed runs? Share it on Instagram or Threads.