The gap between "I've signed up" and "I know what I'm doing"
You've entered a half-marathon. Maybe it was an optimistic Sunday decision, maybe a colleague talked you into it, maybe you just fancied a goal. Either way, race day is in roughly four months and you have a job, probably some commitments that can't be moved, and a life that doesn't care about your training schedule.
Most half-marathon plans online assume you have four or five days a week, a long run window on Sunday morning, and roughly nothing else going on. That's not most people. So here's a more honest picture of what a realistic build-up looks like — and what to expect at each stage.
Weeks 1–4: It's supposed to feel easy (that's the point)
The early weeks of any sensible plan are meant to feel underwhelming. You're running distances that feel almost embarrassingly short, and your body isn't asking for much. This phase isn't about fitness — it's about building a routine around your actual week.
Your main job in the first month is to find your three or four slots and defend them. Not the ideal slots. The realistic ones. Maybe that's a lunchtime run on Tuesday, an early one on Thursday, and a longer outing at the weekend. Figure out what actually fits before you start stacking mileage on top.
Don't add extra sessions because you feel good. The purpose of this block is habit, not heroics. The fitness will come — but only if you're still going in week eight.
Weeks 5–9: The middle, which is where most people wobble
This is the stretch where training stops feeling like a novelty and starts feeling like a commitment. Your long runs are getting properly long — nudging past 90 minutes — and the cumulative tiredness of juggling work and training starts to show up.
A few things tend to happen here. Midweek runs get squeezed by life. You miss a session and wonder if you've derailed everything. The weekend long run starts to feel like a project rather than a run.
All of that is normal. The key adjustment in this phase is to protect the long run above everything else. If a busy week forces you to drop something, drop a shorter midweek run rather than the long one. The long run is where your aerobic base actually builds. A missed 40-minute Tuesday run is not a crisis; a missed long run three weeks in a row is.
Also worth knowing: your pace on longer runs should be genuinely easy. Conversational. Slower than you think is "right." If you're gritting your teeth through your long run, you're going too fast, and the fatigue will compound over the following weeks in ways that feel mysterious but aren't.
Weeks 10–13: The block that actually makes you a half-marathoner
This is where the mileage peaks — typically two or three weeks of your biggest training load before things start to taper off. Your longest run in this block will probably be somewhere between 10 and 12 miles, depending on your plan.
Practically, this is also when work tends to get in the way the most. Murphy's Law of training: your biggest training week and your biggest deadline often share a calendar. When that happens, don't try to cram everything in. Trim the shorter runs, keep the quality sessions (if you're doing any), and get the long run done even if it means shifting it to a different day.
Sleep becomes noticeably more important here. Many people find that their times feel harder in weeks 10–13 not because their fitness has gone backwards, but because they're carrying accumulated fatigue. If that's you, that's broadly the plan working. The taper in the final weeks exists precisely to let your body absorb the work.
Weeks 14–16: The taper, and why it feels wrong
Almost everyone finds the taper unsettling. Your mileage drops, your legs feel strange, and a voice in your head insists you haven't done enough and should be running more. You haven't and you shouldn't.
The taper is when the adaptation actually happens. Your muscles repair, your glycogen stores fill up, and your body quietly catches up with the training it's been absorbing. Doing big sessions in the final two weeks doesn't add fitness — it just adds fatigue you'll be carrying on race day.
The best thing you can do in the taper is keep your short runs going, sleep well, eat normally, and resist the urge to do anything heroic. Sort your race-day kit, know your start time, plan your travel. Keep it boring.
What race day actually needs from you
Turn up rested, start slower than feels right, and trust that the training is in your legs whether you can feel it or not. The first few kilometres will feel pedestrian. That's correct. Banking energy early is the only strategy that works.
If things go sideways — a bad patch, the wall, a slower finish than you imagined — remember that finishing a half-marathon whilst holding down a job and a life is genuinely impressive. The training you did was real, regardless of the clock.
The honest summary
A half-marathon is achievable on three or four sessions a week, over roughly 14–16 weeks, without treating training as a second job. What it requires is consistency over intensity, a willingness to flex the plan when life intervenes, and enough patience not to blow up the early weeks chasing fitness you don't need yet.
Will Powered is built to help you navigate exactly this kind of build-up — adjusting your plan around your real week rather than the theoretical one. Book a demo to see how it works in practice.