Marathon Training: When to Start and How to Prepare
How many weeks you need for a marathon, half marathon or 10K, when to start, what you should already be able to do, and how a sensible build-up — base, volume, marathon-specific work and taper — is structured, with the Swiss races in mind.
Want to line up for the Jungfrau Marathon, SwissCityMarathon Lucerne, Lausanne Marathon or Zurich Marathon? Then don't look only at the race date. What really matters is how regularly you already run today and which distance you want to prepare for.
Here's how to find your start date: count back from the event. For a marathon, plan around 16 to 24 weeks if you already have a running base, for a half marathon 12 to 16 weeks, and for 10 kilometres roughly 8 to 12 weeks.
The short version: A classic marathon plan usually runs 16 to 24 weeks and assumes you already have a running base. A half marathon often needs 12 to 16 weeks, a 10K roughly 8 to 12 weeks. If you're starting almost from scratch, you need far more time to build a durable base first. What matters isn't just how many weeks remain until race day — it's what you already train today.
How long does marathon preparation take?
For a marathon, you normally shouldn't start running regularly only twelve weeks before the race.
A classic marathon plan often runs between 16 and 24 weeks. That assumes, however, that you already have some kind of running base.
| Starting point | Sensible preparation time |
|---|---|
| You already run 3–4 times a week | around 16–20 weeks |
| You run regularly, but not much yet | around 20–28 weeks |
| You're starting practically from zero | at least 6–12 months |
| You're preparing for a mountain marathon | around 20–28 weeks |
| You want to run a half marathon | around 12–16 weeks |
| You want to run 10 kilometres | around 8–12 weeks |
The less running experience you have, the more time you should set aside for building the base.
What should you already be able to do before a marathon plan?
Before the real marathon preparation begins, you should have trained regularly and as pain-free as possible for several weeks.
A commonly sensible starting point is:
- three regular runs a week
- roughly 25 to 40 kilometres a week
- one longer run of at least 12 to 16 kilometres
- no acute complaints
- enough time for training and recovery
These aren't hard entry requirements. Depending on your experience, injury history, training frequency and goal, the right starting point can differ — the figures mainly show that your body is already used to regular running load.
If you can only run a few kilometres right now, that's not a problem. In that case, though, your first goal should be building a stable base — not jumping straight into a full marathon plan.
How marathon preparation is structured
Good preparation isn't simply about running more kilometres every week. It's split into several phases.
Phase 1: Build the running base
The first weeks are about establishing regular training.
Most runs should be easy. You should still be able to hold a conversation and not feel exhausted after every session.
Typical content:
- two to four easy runs a week
- gradually longer runs
- running technique and short strides
- strength work for legs and core
- enough rest days
In this phase, consistency matters more than speed.
Phase 2: Increase volume slowly
Once you run regularly, it's mainly the long run that's built up step by step.
Depending on your fitness, the long runs can later reach roughly 24 to 32 kilometres. Not every runner has to cover 32 kilometres in training, though — duration, weekly volume, experience and recovery capacity matter just as much as the raw distance. And not every week has to be longer than the last.
A sensible build-up also includes quieter weeks in which volume is deliberately cut back. That lets your body adapt to the load.
Increasing too fast, by contrast, raises the risk of complaints in the knee, Achilles tendon, shin or hip.
Phase 3: Train marathon-specific
In the specific phase you prepare deliberately for the demands of race day.
That includes:
- long runs
- sections at planned marathon pace
- easy recovery runs
- tempo or threshold work
- fuelling during longer sessions
- training with your intended race gear
During the long runs you should test which drinks, gels or foods you tolerate. Race day is not the moment for experiments.
Phase 4: Taper
In the last two to three weeks before the marathon, training volume is reduced.
That doesn't mean you stop running entirely. Sessions get shorter, while some intensity can stay in.
The aim is to be recovered on race day without feeling sluggish.
Don't try to make up missed long runs shortly before the marathon. Whatever is missing a few weeks out can't be forced without adding risk.
What does a typical training week look like?
A marathon week could, for example, consist of four runs:
- Monday: rest day or light strength work
- Tuesday: easy run
- Wednesday: rest or supplementary training
- Thursday: tempo session or a run at planned race pace
- Friday: rest day
- Saturday: short, easy run
- Sunday: long run
But there's no single perfect week structure. A plan has to fit your job, your family, your available training days and your recovery.
Three well-planned sessions can be more useful than five sessions you only complete irregularly or while constantly exhausted.
How much of your training should be easy?
The largest part of your run training should happen at an easy pace.
Share of weekly running
Easy
70–80 %
Quality
20–30 % · tempo, intervals, hills, marathon pace
Many runners make the mistake of running their easy runs too fast. As a result, they aren't recovered enough for the sessions that matter.
A simple guide: roughly 70 to 80 percent of your training should be easy.
The faster 20 to 30 percent can be tempo sections, intervals, hill runs or marathon-specific work. The exact ratio depends on your fitness and your plan.
Do you need strength training for a marathon?
Strength training doesn't replace running, but it can support the preparation well. One or two short strength sessions a week can help you cope with the load better.
Useful exercises include:
- squat variations
- lunges
- step-ups
- calf raises
- hip extension
- exercises for core and pelvic stability
During very intense running weeks, strength work should be adjusted. The goal isn't constant muscle soreness, but a more resilient body.
What about a mountain marathon?
A mountain marathon like the Jungfrau Marathon demands different preparation than a flat city marathon.
Beyond general endurance, you should train specifically:
- long climbs
- longer downhill sections
- strength endurance
- walking on very steep sections
- fuelling over several hours
- suitable shoes and gear
Even if two races are both 42.195 kilometres long, their demands can differ sharply. For a mountain marathon you should therefore plan more preparation time and train as regularly as possible on comparable terrain.
Jungfrau Marathon: how to train for a mountain marathon
The Jungfrau Marathon is a mountain marathon. If you already have a running base, plan more like 20 to 28 weeks and train as regularly as possible on comparable terrain.
The specific phase includes:
- deliberate hill runs with long climbs
- controlled downhill running
- strength endurance for long ascents
- testing fuelling over several hours
- breaking in shoes and gear during training
If only a few weeks remain before the start, shift the focus to fine-tuning: a last few specific hill runs, testing fuelling and gear, then reducing the load. Anyone who hasn't done longer runs and hardly any climbing, though, should review the goal critically — safe mountain-marathon fitness can't be built in a few weeks.
Lucerne and Lausanne: how to use a 12- to 16-week training block
A training block of around 12 to 16 weeks can suit these city races well — provided you already have a running base. What's realistic in that time depends on the distance.
Marathon
A marathon is realistic in such a block mainly if you've already run regularly for several months and are used to long runs. Without that base, the half marathon is the smarter entry point.
Half marathon
For a half marathon, a 12- to 16-week block is a good window. Even less experienced runners can build up sensibly, as long as they can already run roughly five to ten kilometres easily.
10 kilometres
For a 10-kilometre race, such a block is plenty for many beginners. Training can start as a mix of running and walking and be increased gradually later.
Zurich Marathon: how to build up for the long term
When there are still many months until the race, you have time for a calm, long-term build-up.
That's especially helpful if you:
- are planning your first marathon
- currently run only irregularly
- want to lose weight
- are returning after a break
- are injury-prone
- want to reach a specific target time
You don't have to start with 30-kilometre runs straight away. An early start allows a calm build-up:
- establish regular running
- increase weekly volume slowly
- develop longer runs
- work deliberately on pace and endurance
- move into the marathon-specific phase
The earlier you start, the less you have to force individual training weeks.
Which distance is realistic for you?
The right distance depends above all on where you are today. If you don't run regularly yet, build a stable routine first with a 5K or 10K goal. If you already run five to ten kilometres, a half marathon is a realistic next step. And if you've run three to four times a week for months and tolerate longer runs, you can take on a structured marathon preparation — with extra time for climbing and strength endurance if it's a mountain marathon.
The longest distance isn't automatically the best goal. A well-prepared half marathon is often more sensible than a marathon you'd have to rush your training for.
Common mistakes in marathon preparation
Many problems come not from too little motivation, but from poor load management.
The most common mistakes include:
- increasing weekly volume too fast
- running every run too fast
- making up long runs at short notice
- skipping recovery days
- training on despite pain
- testing fuelling only during the race
- adopting a plan that doesn't match your level
A training plan should give you structure. But it shouldn't force you to ignore warning signs or your actual training history.
What happens with missed sessions?
You don't have to make up every missed session.
If you've skipped a single easy run, you can usually just carry on with the plan.
After several missed training days, illness or unusually high load, on the other hand, the plan should be adjusted. It's often more sensible to reduce volume temporarily than to jump straight back in at the originally planned point.
The calendar tells you when — your training tells you how
GetMyCoach builds your personal training plan to fit your goal, your level and your available training days. Your completed sessions are taken into account, so your plan follows your actual progress, not just the calendar.
Frequently asked questions
When should I start marathon training?
Plan around 16 to 24 weeks for a classic marathon, provided you already have a running base of roughly 25 to 40 kilometres a week. As a beginner, count on more like 6 to 12 months, because you first have to build a durable foundation.
How long does half-marathon preparation take?
For a half marathon, 12 to 16 weeks are often enough if you can already run roughly five to ten kilometres easily. Even less experienced runners can build up sensibly in that window.
How many kilometres per week do I need for a marathon?
Before starting a marathon plan, roughly 25 to 40 kilometres a week is a good starting point. Volume rises through the preparation, and the long runs later reach around 24 to 32 kilometres depending on your fitness.
What percentage of run training should be easy?
Roughly 70 to 80 percent of your runs should be at an easy pace where you can still hold a conversation. The remaining 20 to 30 percent are tempo sections, intervals or marathon-specific work.
Do you need strength training for a marathon?
Strength training doesn't replace running, but it supports it well. One or two short sessions a week for legs and core can help you cope with the running load and prevent complaints.
Is 12 weeks enough for a marathon?
A full marathon in 12 weeks is only realistic if you've run regularly for months and are used to long runs. If you're starting almost from scratch, a half marathon or a 10K is the more sensible first goal.
The bottom line: start to match where you are now
For a classic marathon preparation, plan roughly 16 to 24 weeks. As a beginner you need far more time, because you first have to develop a durable base.
For a half marathon, 12 to 16 weeks are often enough; for a 10-kilometre race, around 8 to 12 weeks.
What matters isn't only how many weeks remain until the race. What matters is what you already train today.
Last updated: July 2026. This article is general training information, not medical advice. If you have pre-existing conditions or complaints, are pregnant, or are returning from a longer break, seek individual advice before an intensive marathon preparation.