The hardest run of any comeback is the first one, and it’s not because of your fitness.
It’s because you remember what you used to be able to do. You head out planning a gentle 5km, because 5km used to be nothing, and somewhere around the two-kilometer mark your body makes it very clear that this is no longer a warm-up. You walk home slightly humiliated, calves already muttering, and quietly decide you’ll start properly next week.
Then next week arrives, and you don’t go, because you don’t fancy feeling like that again. 🙃
That’s the whole trap, and almost everybody falls into it. Not because they’re unmotivated, but because they started at the level they remember instead of the level they’re at.
Your fitness comes back faster than your legs
This is the single most useful thing to understand about a running comeback, and it explains most of the injuries that happen during one.
Your heart and lungs adapt quickly. Within two or three weeks of consistent running, your breathing settles, and the effort starts to feel manageable again — especially if you’ve been cycling or doing anything else in the meantime, because that base carries over.
Your tendons, bones, and connective tissue do not work on that timescale. They adapt in months, not weeks. And they’re the things absorbing the impact every single time your foot hits the ground.
So there’s a window — usually somewhere around weeks three to six — where you feel great, your breathing is fine, and your structures are still nowhere near ready for what your enthusiasm wants to do. That’s when people get hurt. Not on the horrible first run. On the good run three weeks later, when it finally felt easy, they added four kilometers because they could.
Comeback injuries don’t happen on the day it feels hard. They happen a few weeks later, on the day it finally feels easy.
The rule everyone quotes is probably the wrong rule
You’ve heard the 10% rule — never increase your weekly mileage by more than 10%. It’s in every running plan ever written.
It’s also on shakier ground than its popularity suggests. It rests on remarkably little evidence, and the study most often cited in its defense didn’t actually show it prevented injuries.
More recent work looking at thousands of runners found something more useful: it wasn’t the weekly total that predicted injury. It was the single big run — one session noticeably longer than anything you’d done in the previous month. Runners who spiked a single run well beyond their recent longest had substantially higher rates of overuse injury, while week-to-week mileage changes barely predicted anything.
Which matches what actually happens on a comeback, doesn’t it? Nobody hurts themselves by adding an extra slow kilometer over a week. They hurt themselves on the Sunday they felt good and did double their usual.
So the rule I’d rather you carry: don’t let any single run be dramatically longer than your longest run of the past month. Build the week gradually if you like — but guard the long one carefully.
Before you start: two honest checks
Can you walk briskly for 30 minutes without pain or a limp and feel fine afterward? That’s the gate clinical return-to-running protocols use, and it’s a sensible one. If walking still hurts, running will hurt more.
Is this a comeback or a rehab? Important distinction. If you’re coming back from a break — busy, illness, life, winter, motivation, a long stretch of just not running — this plan is for you. If you’re coming back from an actual diagnosed injury, get a physio or biokineticist to build your progression instead. Their plan will have a similar shape, but the details will be specific to what went wrong, and that matters. 🩷
The four-week plan
Three sessions a week, never on consecutive days. That gap is not optional padding — it’s when the adaptation happens, and it’s the main thing protecting you during the weeks your legs are behind your lungs.
All the running is slow. Conversational. If you couldn’t answer a question comfortably, you’re going too fast. This will feel ridiculous at first. Do it anyway.
Week 1 — 20 minutes before the finishing walk, three times
5-minute brisk walk to warm up. Then repeat 5 times: 1 minute running, 2 minutes walking. Finish with a few minutes of walking.
Yes, one minute. I know. Start here anyway — this is the week that decides whether you’re still doing this in October.
Week 2 — 25 minutes before the finishing walk, three times
5-minute walk. Then repeat 5 times: 2 minutes running, 2 minutes walking. Walk to finish.
Week 3 — 29 minutes before the finishing walk, three times
5-minute walk. Then repeat 4 times: 4 minutes running, 2 minutes walking. Walk to finish.
This is the week it starts feeling good. This is also the week to not get carried away. 😅
Week 4 — 32 minutes before the finishing walk, three times
5-minute walk. Then repeat 3 times: 7 minutes running, 2 minutes walking. Walk to finish.
By the end of week four, you’re running about 21 minutes in a session, in chunks, comfortably. That’s a genuine base — and it’s roughly 3–4km of running for most people, depending on pace.
And then what?
Keep going in the same shape. Extend the running blocks, shrink the walking ones, and let one of the three runs slowly become slightly longer than the others. A continuous 30 minutes is a good next target, and it’ll arrive around week seven or eight without you having to force it.
Repeating a week is not failing
If a week felt hard, do it again. If you missed two sessions, drop back one week and rebuild. If something is niggling, stay where you are until it settles.
The plan is a suggestion, not a contract. Nobody is checking. And a comeback that takes eight weeks and holds is infinitely better than one that takes four weeks and ends with you back on the couch with a sore Achilles, which — as I wrote about in this rather less dignified piece — I have personally researched more thoroughly than I’d like.
On soreness: general muscle achiness in the day or two after a run is normal and settles. Sharp pain, pain that gets worse as you run, pain that changes how you move, or anything in a specific spot that shows up in the same place every time — stop and get it looked at. Those are different animals entirely.
🩷 Write it down, actually
Comebacks are won by consistency, and consistency is much easier to see than to remember. A simple log — what you did, how it felt, anything niggling — means you’ll notice the pattern before it becomes an injury, and you’ll have proof you’re progressing on the days it doesn’t feel like it. The Weekly Training Log in the shop does exactly this, and nothing more complicated.
Four things that make it stick
- Fix the days, not the distance. Decide which three days you run and defend them. What you do on those days matters less than the fact that they happen.
- Don’t race your old self. Comparing today’s pace to the pace you held four years ago is the fastest way to quit. Different body, different life, different day.
- Keep cross-training if you’re already doing it. Cycling maintains the aerobic side beautifully while your legs catch up. If you’re already riding indoors, that base is doing you a real favor here.
- Add two short strength sessions. The single best thing for making tendons and bone tolerate running load — and it matters more after 40, which I’ve written about here.
The bit nobody puts in the plan
Starting again is a bit humiliating, and I don’t think we say that enough.
Walking in the middle of a run when you used to run 21km. Being overtaken by someone who looks like they’re barely trying. Getting home after twenty minutes, genuinely tired. All of it sits somewhere between annoying and quietly upsetting, and no amount of sensible progression advice touches that part.
What helped me was deciding the first month wasn’t running. It was becoming a person who runs again, which is a different job with a different measure of success. You don’t pass or fail week one based on how it felt. You pass it by turning up three times.
Then one day, somewhere in month two, you’ll be out and realize you’ve stopped thinking about how it’s going, and you’ll just be running. That’s the whole thing. That’s what you’re building towards. 🩷
If it’s the bike rather than the shoes, getting back on the bike after a break is the cycling version of this. And if you’re wondering why the comeback feels harder than the last one did, this one on recovery in midlife might explain a few things.
You are not starting from scratch. You are starting from experience — and that is a completely different starting line.
🩷The Endurance Diaries🩷
