If you're starting from genuinely nothing (no regular running, maybe not much regular exercise at all), and a half marathon is the goal, good. It's a great goal. But almost everything you'll find searching "couch to half marathon" skips the part that actually matters: what happens *before* the 12-week plan. That's what this guide is for.
I'll say the unglamorous thing up front, because I'd rather you hear it from me than learn it the hard way: couch to half marathon almost always takes longer than 12 weeks. Not because 12 weeks isn't enough plan: it's a perfectly good structured plan, once you're ready for it. It's that "ready for it" is a separate stage most guides pretend doesn't exist.
Twelve weeks is the minimum for a structured half marathon plan, and that number holds for someone who's already running 3-4 times a week and comfortable with 5-8km. It is not the minimum for someone starting from the couch. If that's you, the 12-week plan doesn't start on day one of your training. It starts once you've built a base to run it from.
So the honest total looks more like this: 6-10 weeks of walk-run base-building, then the 12-week structured plan on top. Call it 18-22 weeks, give or take, from true zero to a half marathon start line. That's roughly 4-5 months. It sounds like a lot until you remember the alternative: squeezing a couch start into 12 weeks flat usually ends in a shin splint around week 7 and a DNS, not a finish line.
Running is supposed to be fun and sustainable. A timeline that respects where you're actually starting from is how it stays that way.
Before any of the Base → Support → Specific plan structure applies to you, you need something to build it on top of. That something is a walk-run base, and it's not a lesser version of training. It's the actual first phase for someone starting from zero.
A simple starting pattern: 1 minute running, 2 minutes walking, repeated for 20-30 minutes, 3-4 times a week. As weeks pass, the run intervals get a bit longer and the walk intervals get a bit shorter, not on a fixed schedule, but as it starts feeling genuinely comfortable rather than gritted-teeth manageable. There's no prize for rushing this part.
You're ready to call the base "built" when you can run continuously for around 20-30 minutes, a few times a week, at a conversational effort: not fast, not impressive, just sustainable. That's the line where structured half marathon training actually begins to make sense.
Once that walk-run base is genuinely in place (not "I did it once and felt good," but a few consistent weeks of it), you step into the same three-phase structure I use for every half marathon plan, beginner or otherwise:
The mistake I see most from a couch start is jumping straight into a beginner half marathon plan on week one, treating the walk-run stage as optional. It isn't a warm-up you can skip if you're keen. It's Phase Zero, and the whole structure above depends on it existing first.
New runners get hurt for one main reason: doing too much, too soon, without enough recovery in between. The single biggest guardrail against that is a rule I never bend, at any level: never two hard days back to back. For a beginner, "hard" doesn't just mean speed work: running on tired legs two days running, before your tissues have adapted, counts too.
A few other basics that matter more at this stage than any other:
You don't need a race on the calendar to know when to move from walk-run base into the 12-week structured plan. You need these, roughly:
Tick those, and you're ready for the same 12-week structure any beginner half marathon plan uses. See the half marathon training plan for beginners guide for exactly how that plan is built week by week, including the sample week and the non-negotiables that carry through from here.
I've run 13 half marathons myself (PB 1:23:45, nowhere near that on my first one). RunLetters Half Marathon Coaching pairs you with a real coach, not an app, who meets you exactly where you're starting from (walk-run base and all) and adjusts the plan as training actually goes, not as it looks on paper.
See the coaching programYes. I've coached people from genuinely zero running to a half marathon finish, and they enjoyed it. The condition is time: a walk-run base built before the structured plan starts, not instead of it. Skip the base and it turns into "couch to injury" instead.
Longer than 12 weeks, honestly. The 12-week plan is the minimum once a base exists: 6-10 weeks of walk-run base-building usually comes first from a true couch start. Total runway is often 18-22 weeks, roughly 4-5 months.
Walk-run intervals: something like 1 minute running, 2 minutes walking, for 20-30 minutes, a few times a week. Straight walking doesn't build the specific adaptation running needs; straight running too soon is how a beginner base turns into a beginner injury.
Handle it case by case, never crammed. Sometimes you resume where you left off, sometimes you repeat a week of base-building before moving on. What you never do is double up sessions to "catch up": that just stacks fatigue where your body wasn't expecting it.