How to Prepare for Your Upcoming Marathon — Half and Full

The half marathon and the marathon are not the same race at different lengths.

The half is a fitness event. Train consistently, pace it sensibly, and your fitness will carry you to the line. The full is a fuelling and pacing problem wearing an endurance event's clothes — and it treats anyone who prepares for it as a long half with real hostility.

Both are absolutely achievable for an ordinary person with a job and a finite amount of time. They just need different plans. Here's what they share, and where they part company.

Start with an honest timeline

Half marathon: 10–14 weeks, if you can currently run 5km without stopping.

Full marathon: 16–20 weeks, if you already have roughly 25–30km a week in your legs.

Below those starting points, spend four to eight weeks quietly building base mileage first. This is the least glamorous advice in the article and the most important: nearly every runner who arrives at a start line injured got there by compressing the build. Roughly half of marathon trainees pick up some kind of niggle along the way, and almost all of those come from adding volume too quickly.

The flip side is genuinely encouraging. Follow a sane timeline and the distance stops being the hard part. Most people who finish a marathon were not gifted runners. They were runners who didn't skip weeks.

What a realistic goal looks like

Half marathon. Most first-timers finish somewhere between 2:00 and 2:45. Breaking two hours is the classic second-race target and well within reach of a consistent 10–14 week build.

Full marathon. Most first-timers land between 4:00 and 5:30. Sub-four is the goal everyone knows; sub-five is a perfectly good race that most people underrate.

And for a first attempt at either, the honest target is: finish it, having paced it well, without the last 5km being a survival exercise. That gives you a number to beat, which is where the enjoyable part of running long distances actually begins.

On walking. Planned walk breaks — a minute of walking every mile, or at each aid station — are a legitimate, well-established strategy, not a failure state. If it's your first, plan them deliberately rather than falling into them at 30km.

The one habit that matters most: run easy

The most common mistake in amateur running is simple. Easy runs are too hard, and hard runs are too easy.

Roughly 80% of your weekly running should be genuinely easy — conversational, the pace at which you could hold a phone call in full sentences. The remaining 20% carries the intensity.

Easy running is where the adaptations happen: capillary density, mitochondria, fat oxidation, tendon resilience. But it only works if you actually run it easily. If every run drifts into the grey middle zone, you collect the fatigue without collecting the fitness. This is the single change that transforms most amateur runners, and it costs nothing except your ego on the days you're overtaken.

If you're running the half

A typical mid-build week:

• 3–4 easy runs

• 1 quality session — intervals (say 6 × 800m) or a tempo run of 20–30 minutes at comfortably hard effort

• 1 long run, building from 10km toward 18–21km

• 1–2 strength sessions

• Peak volume: roughly 40–55km per week

Long runs are refreshingly simple here. Add 1–2km every second week and pull back every fourth week to let the work land.

Fuelling is barely a problem. The half sits just inside the limit of your stored glycogen for most people. A solid carbohydrate meal beforehand and possibly one gel around the 60-minute mark covers it.

Pacing: hold back for the first 5km. Your race is decided between 15km and the finish, and the only way to have anything left there is to feel slightly restrained early. Set a target pace, run the first three kilometres a touch slower than it, and start working from halfway.

If you're running the full

A typical mid-build week:

• 4–5 easy runs

• 1 quality session — often a marathon-pace segment inside a longer run

• 1 long run, building toward 30–35km

• 1–2 strength sessions

• Peak volume: roughly 55–80km per week

The long run has a second job here. Beyond endurance, it teaches your body to burn fat efficiently and to absorb fuel while moving. Build to two or three runs in the 30–35km range, spaced at least two weeks apart, and run part of them at goal pace in the back half. A 26km run finishing with 10km at marathon pace is worth considerably more than 32km of shuffling.

You don't need to run the full 42.2km in training. The recovery cost outweighs anything you'd gain, and every sensible plan leaves that final stretch for race day.

Fuelling is the whole game. You will run out of stored carbohydrate — everyone does. The question is only how well you manage it.

• Carb loading: in the two to three days before the race, push carbohydrate intake high — commonly cited targets are around 8–10g per kilogram of bodyweight per day — while cutting fibre and fat.

• During the race: aim for roughly 60–90g of carbohydrate per hour. That is far more than most amateurs take, and your gut has to be trained for it exactly as your legs are trained for mileage. Practise it on every long run for the final eight weeks.

• Hydration: drink to thirst, adding electrolytes in heat. Over drinking is a real and occasionally dangerous mistake.

Pacing: banking time early is a myth. Every second gained in the first 10km costs you several in the last 10. Carry three goals — an ambitious A, a realistic B, and a C that means finishing strong — and decide which one you're running around the 25km mark, not on the start line.

Nothing new on race day. Not the gels, not the shoes, not the breakfast.

Strength work, for both

Two short sessions a week are enough, and they meaningfully reduce injury risk. Prioritise single-leg work — split squats, step-ups, single-leg deadlifts — plus calf raises with both straight and bent knee, and hip and glute strength. Running is a repeated single-leg impact task, so training only bilaterally leaves an obvious gap.

Learn the warning signs and respect them: pain that worsens as a run goes on rather than warming up, pain that changes how you move, or pain still present the next morning. Those are stop-and-assess signals, not push-through signals. A week off in month two is cheap. A stress fracture in month four ends the whole project.

The taper

Half: 10–14 days. Cut volume by 30–40%, keep some intensity.

Full: 2–3 weeks. Drop volume by roughly 40% in the first taper week and 60% in race week, keeping short segments at race pace so your legs remember the feeling.

Fair warning: tapering feels terrible. You'll be sluggish, restless and quietly convinced you're losing everything you built. This happens to almost everyone and means nothing. Your only jobs in the last ten days are to sleep, eat carbohydrate, and resist the urge to prove yourself with one final big session.

Race week

• Lay out your kit and pin your bib the night before

• Rehearse breakfast timing in training — most people eat 2.5–3 hours before the start

• Write your gel schedule by kilometre, on your hand if that's what it takes

• Check the elevation profile and plan your effort around the hills

• Have a wet-weather plan and a hot-weather plan

The takeaway

Both races reward the same three things: consistency, the patience to run easy when you'd rather run hard, and a plan you actually follow. The marathon asks for one more — a fuelling strategy rehearsed until it's boring.

Get the timeline right, respect the taper, and start slower than you want to. That covers most of the distance between a race you endure and a race you'll want to do again.