How to Train for a Half Marathon: The Complete Guide
Training for a half marathon is about much more than gradually running further each weekend.
To prepare well for 21.1 kilometres, you need to develop your aerobic fitness, build the durability to keep running as fatigue accumulates, introduce the right quality training at the right time, recover properly, practise your fuelling and pacing, and arrive at the start line fit rather than exhausted from your preparation.
But that doesn’t mean you need to train as much as possible.
My philosophy when designing training programmes is straightforward:
I don’t try to maximise the amount of training an athlete can complete. I try to minimise the amount of training required to achieve that athlete’s goal.
That’s an important distinction.
Someone preparing to complete their first half marathon doesn’t need the same programme as an experienced runner trying to break 90 minutes. A runner who can train three days each week needs a different structure from someone who runs six days and recovers well between sessions.
There isn’t one perfect half marathon programme for everybody.
There are, however, some fundamental principles that I use when preparing athletes for the distance.
In this guide, I’ll take you through the complete process: where to start, how long to train, how often to run, how I use my Level I–V intensity system, how training changes as race day approaches, long runs, quality sessions, strength and flexibility training, fuelling, tapering, pacing and what to do when training doesn’t go according to plan.
Whether you’re preparing for your first half marathon or trying to run your fastest 21.1 km, the objective is the same:
Arrive at race day healthy, appropriately trained and ready to perform.
Who Is This Half Marathon Training Guide For?
This guide is designed for a broad range of runners.
You might be preparing for your first half marathon and wondering whether you’re capable of covering 21.1 km.
You might have already completed several and want to improve your time.
Or perhaps you’re an experienced runner chasing a performance goal such as breaking two hours, 1:45, 1:30 or faster.
The details of your training will change considerably depending on where you’re starting and where you want to finish.
The principles don’t change nearly as much.
One of the biggest mistakes you can make is choosing your training according to the runner you want to be rather than the runner you are today.
Start with your current fitness.
Then progressively build from there.
How Fit Should You Be Before Starting Half Marathon Training?
For most of my structured half marathon programmes, I like runners to be capable of running continuously for approximately 30 minutes before beginning.
You don’t need to be fast.
You don’t need to have previously raced 10 km.
And you certainly don’t need to be able to run anywhere close to 21.1 km.
But being able to comfortably run continuously for around 30 minutes gives us a useful foundation from which to begin developing your half marathon fitness.
What If You Can’t Run for 30 Minutes Yet?
That’s not a reason to abandon your half marathon goal.
It simply means you’ve got an earlier step to complete.
For athletes coming from little running or a run/walk background, a Starter programme can progressively develop the ability to run continuously for 30 minutes.
Once you’ve developed that foundation, you’re in a much better position to begin your specific half marathon preparation.
This is also one reason why I prefer athletes to plan their events well in advance.
If you’ve got plenty of time, there’s no need to rush.
Build the runner first.
Then train the runner for the half marathon.
How Long Does It Take to Train for a Half Marathon?
You’ll commonly see half marathon programmes lasting 12, 16, 20 or 24 weeks.
I use all of those durations.
But I don’t believe there’s a magic number of weeks that everybody needs.
A lot depends simply on how far away your race is.
If you’ve entered a race that’s 13 weeks away, a 12-week programme makes sense.
If you’ve planned six months ahead, we can use a 24-week programme.
And if your goal event is even further away, that’s an opportunity rather than a problem.
We can spend time developing your general fitness before beginning the 24-week specific preparation at the appropriate point.
More Preparation Time Is Usually Better
Generally, I’d rather have more time than less.
More time allows us to progress training gradually.
It gives us room to develop aerobic fitness.
It allows adaptations to occur without constantly rushing towards the next stage.
And, importantly, it gives us some margin for real life.
Illness happens.
Work gets busy.
Family commitments appear.
Sometimes you miss training.
A longer preparation means one disrupted week doesn’t have to become a crisis.
What If You Have Several Half Marathons Planned?
Not every race needs a completely new 12-, 16- or 24-week programme.
You may have several events within the same season.
If you’ve completed one half marathon and your next race is only eight weeks later, I’m not going to send you back to the beginning and pretend we’re starting again.
We work from the fitness you’ve developed for the first event.
That might mean an eight-week programme incorporating recovery from race one, an appropriate period of training and preparation for race two.
If you have several races planned, we also need to decide which events are priorities.
You don’t necessarily need to peak equally for every race.
That’s where periodisation becomes particularly useful.
How Many Days a Week Should You Run for a Half Marathon?
I consider three runs per week the minimum for dedicated half marathon preparation.
For many runners, however, my preference is four to five runs per week.
That doesn’t mean five is automatically better than four, or six is automatically better than five.
More training is only useful if you can adapt to it.
The appropriate frequency depends on factors including:
- Your training history
- Your aerobic efficiency
- Your chronological age
- Your training age
- Your injury history
- Your ability to recover
- Your available time
- Your performance goals
- Other training you’re completing
I generally like endurance athletes to be doing something on most days of the week, but that doesn’t mean every day needs to be a run.
Strength training, cycling, swimming and flexibility training may all have a place depending on the athlete.
What Does a Half Marathon Training Week Look Like?
Regardless of whether you’re running three, four, five or six days per week, I want each session to have a purpose.
For a runner training three times per week, we might have a quality session, a steady run and a long run.
As we add training days, most of the additional running isn’t another hard workout.
It’s predominantly additional aerobic running.
That’s important.
One of the easiest ways to make a programme harder is simply to add more quality sessions.
That doesn’t necessarily make the programme better.
For most athletes, the majority of their running should remain controlled aerobic work.
My general approach is approximately an 80/20 distribution, with around 80% of running time at Level II and approximately 20% involving quality work.
The exact distribution will vary, but the principle matters:
Most of your training should not feel hard.
Understanding Training Intensity: My Level I–V System
I prescribe running using five primary intensity levels.
Level I — Easy/Recovery
Level I is very easy running and is used predominantly as recovery within higher-intensity sessions.
I don’t typically prescribe large amounts of standalone Level I running for half marathon athletes.
Level II — Endurance/Conversational
This is the foundation of the programme.
You should be able to maintain a conversation.
Most steady running and most long-running volume sits here.
For pace, Level II is approximately 81–89% of threshold pace.
Level III — Tempo
Level III is controlled but purposeful running.
It’s harder than your normal endurance running but still sustainable.
For pace, that’s approximately 90–94% of threshold pace.
Tempo training becomes particularly important as we move closer to the half marathon.
Level IV — Threshold
Level IV is threshold running.
It’s a substantially harder intensity that we use in carefully structured intervals rather than turning every training session into a race.
For pace, Level IV is approximately 100–103% of threshold pace.
Level V — VO₂ Max
Level V is very hard running.
For pace, we’re approximately 110–120% of threshold pace, depending on the session.
These are relatively short efforts and make up only a small proportion of half marathon preparation.
Why Easy Running Is So Important
One of the most common problems I see with recreational runners is that they run their Level II sessions too fast.
They believe that if running faster makes them fitter, then running every session a little faster must make them fitter faster.
Unfortunately, training doesn’t work that way.
When a Level II session becomes Level III, you’ve changed the training stimulus.
You’ve also increased the fatigue and recovery cost.
Do that repeatedly and you can arrive at your genuinely important quality sessions already tired.
Easy running isn’t wasted running.
It’s where a huge amount of your aerobic development takes place.
Periodising Your Half Marathon Training
Your training shouldn’t look identical 20 weeks from race day and two weeks from race day.
As the event approaches, the training stimulus should evolve.
I divide half marathon preparation into four main phases:
Foundation & Injury Prevention → Early Quality → Transition Quality → Final Quality
Each has a different emphasis.
Foundation & Injury Prevention
This phase is about establishing the foundation required for everything that follows.
Running is predominantly Level II.
We’re developing aerobic fitness, consistency and durability without trying to prove fitness in every session.
The quality element might simply involve stride-outs.
For example, within a 60-minute run you might complete:
25 minutes Level II → 10 × 20 seconds Level V / 40 seconds Level II → 25 minutes Level II
The duration can be adjusted according to the athlete.
Those short stride-outs introduce speed without creating the training load associated with a full high-intensity session.
Early Quality
Once the foundation has been established, I start introducing more substantial quality training.
The predominant quality stimulus during this phase is generally hill repetitions.
Hills are an excellent way of developing running-specific strength while maintaining the movement patterns of running.
For athletes who are training frequently enough and recovering well, a second quality session might involve tempo running.
But not everybody needs two quality sessions.
Transition Quality
The next phase places greater emphasis on threshold training.
This is where Level IV intervals become increasingly important.
Depending on the athlete’s experience, training frequency and ability to recover, a second quality session may involve threshold or tempo work.
Again, I’m not adding sessions simply because we can.
A runner training five or six days per week and chasing a high-performance goal may benefit from two quality sessions.
A recreational athlete training three or four times per week may be much better served by one.
Final Quality
As race day gets closer, the training becomes increasingly specific to half marathon performance.
Tempo running at Level III becomes a priority.
For appropriate athletes, a second quality session might involve lower-training-stress Level V work.
The aim isn’t to suddenly train harder than ever.
It’s to ensure the training increasingly reflects the demands you’re preparing to meet on race day.
Your Long Run: The Most Important Session of the Week?
When runners hear the term quality session, they usually think of intervals, hills or threshold running.
But for half marathon preparation, I’d argue that your long run is potentially your most important quality stimulus.
You need to develop the ability to keep running as fatigue accumulates.
The long run does exactly that.
For most of the programme, your long run should be predominantly Level II.
The objective isn’t to race it.
You’re building endurance.
How Long Should Your Longest Half Marathon Training Run Be?
For most half marathon runners, I use approximately two hours as the maximum long run.
There’s a point where making the run longer creates more recovery cost than additional benefit.
If you run substantially beyond two hours and then require several days to recover, you’ve potentially compromised the training planned for the following days or even the following week.
That’s not a good trade.
Remember, we’re not judging an individual workout solely by how impressive it looks on Strava.
We’re asking how that session contributes to the whole programme.
Progressive Long Runs
As athletes become more experienced, I’ll sometimes introduce progressive long runs.
These become particularly relevant for Performance and Elite athletes, but I also use them with recreational runners who have a sufficiently long build-up and appropriate training background.
Instead of running the entire session at Level II, the intensity increases later in the run.
That increases the training stress and, importantly, teaches you to run faster with fatigued legs.
That has obvious relevance to half marathon racing.
But progressive long runs aren’t something we need from week one.
First build the endurance.
Then add complexity where it provides a worthwhile stimulus.
How Do You Know Whether Your Training Is Working?
Training shouldn’t simply be a series of workouts leading blindly towards race day.
We need opportunities to assess progress.
I often change the training stimulus approximately every four to six weeks, depending on the overall duration of the programme.
Around these transitions, I’ll frequently include a 5 km time trial.
That gives us several useful pieces of information.
It provides a performance benchmark.
It allows us to compare fitness with previous testing.
And it helps us establish appropriate training intensities for the next phase.
A parkrun can work extremely well for this purpose.
I frequently use recent 5 km performance to help establish threshold values and guide training.
How Do You Set a Realistic Half Marathon Goal?
Your half marathon goal should be based on evidence rather than wishful thinking.
A recent 5 km time trial or parkrun is one of my preferred starting points.
But it isn’t the only option.
A recent 10 km race, previous half marathon or marathon can also give us useful information.
I use Jack Daniels’ VDOT methodology to relate performance over one distance to predicted performance at another.
If an athlete hasn’t raced recently, we can also look at training performances, including interval sessions, to help estimate current capability.
The important point is that your goal pace needs to reflect your current fitness.
You can have the world’s best pacing strategy, but it can’t rescue a goal that was unrealistic from the start.
Should Half Marathon Runners Strength Train?
Maybe.
Strength training is useful, but I don’t believe every runner automatically needs to add several gym sessions simply because they’re training for a half marathon.
Strength training has an opportunity cost.
If adding gym work means you’re sacrificing important running or compromising your recovery, it may not be the best use of your available training time.
But there are situations where strength work earns its place.
That might include rehabilitation, an identified weakness, maintaining strength as you age or addressing a genuine performance limitation.
Once we’ve decided it belongs, my philosophy is:
Train your sport to improve your sport. Strength train to get stronger.
I periodise strength training through:
Strength Endurance → Basic Strength → Specific Power → Strength Maintenance
And importantly, I fit that training around the running rather than allowing it to compromise the key running sessions.
For a deeper explanation, read:
Strength Training for Half Marathon Runners: Do You Need It, and How Should You Use It?
What About Cross-Training?
Cross-training needs context.
If you’re a triathlete preparing for a half marathon within a broader triathlon programme, swimming and cycling will obviously remain important parts of your training.
They also contribute to your overall aerobic workload.
Similarly, a runner completing gym-based strength work is accumulating additional training stress even though those sessions aren’t runs.
That’s why I don’t look at running frequency in isolation.
A runner completing five runs per week has a different total workload from a triathlete completing three runs alongside swimming and cycling.
Cross-training can provide useful aerobic conditioning while reducing some of the musculoskeletal loading associated with running.
But if your goal is specifically to improve your half marathon performance, remember the specificity principle:
You still need to run.
Don’t Forget Flexibility Training
Rest days don’t necessarily mean doing absolutely nothing.
I regularly prescribe 30 minutes of flexibility training on recovery days.
For some athletes that’s once per week. For others it may be twice.
Running involves repeatedly moving through a relatively limited range of motion. Flexibility training gives us an opportunity to work through a greater range of motion and maintain the mobility required for an effective running stride.
It can also form part of the athlete’s overall recovery strategy.
The session predominantly targets the muscle groups involved in running while still incorporating the whole body.
It’s not physically demanding in the same way as a run or gym workout.
That’s precisely why it fits so well on a recovery day.
Recovery Is Part of Half Marathon Training
Training creates the stimulus.
Recovery allows your body to adapt to it.
You don’t become fitter simply because you completed a hard workout.
You become fitter when your body responds appropriately to that workout.
That’s why I don’t want every day to become a competition.
Sleep matters.
Nutrition matters.
Easy training matters.
Flexibility training matters.
And sometimes doing less is exactly what allows you to improve.
What Should You Do If You Miss Training?
You will probably miss some training.
That’s normal.
You might become ill.
Your children might become ill.
Work might suddenly demand more of your time.
You might travel.
Or life might simply get in the way.
Don’t try to cram all of your missed training into the following few days.
The programme was designed with a particular balance between training stress and recovery.
Trying to catch up compresses that workload into a shorter period, removes recovery opportunities and can increase your risk of overload, illness or injury.
If you miss a session, sometimes the best response is simply to move on.
If you’ve missed several sessions or a substantial period of training, then the programme itself may need adjusting.
Don’t try to repay a training debt.
There isn’t one.
What If You Get Sick or Injured?
The same principle applies.
Your priority is getting healthy enough to train consistently again.
Trying to train through illness or rushing back from an injury because you’re worried about missing your programme can turn a relatively small interruption into a much bigger one.
Once you’re ready to return, don’t automatically jump straight back into the training that was originally scheduled.
Where you restart depends on how long you’ve been away, why you stopped and how you’re responding as you return.
The calendar doesn’t know you’ve been sick. Your body does.
Adjust accordingly.
Fuelling for Your Half Marathon
Race-day fuelling isn’t something to think about for the first time on race morning.
It needs to be practised during training.
I keep my approach relatively simple.
The Day Before
Make sure you’re properly hydrated.
Eat a carbohydrate-rich meal to help top up your carbohydrate stores.
Hydration is particularly important because storing carbohydrate also requires water — approximately three grams of water for each gram of carbohydrate stored.
The objective isn’t to force enormous amounts of food or fluid into yourself.
It’s to arrive at race morning appropriately fuelled and hydrated.
Race Morning
I generally recommend eating breakfast approximately two hours before the start.
Keep it relatively:
Low fibre. Low volume. Familiar.
Race morning isn’t the time to experiment with a new breakfast because somebody on the internet said it was perfect for runners.
You want enough time for the meal to digest without creating unnecessary gastrointestinal distress.
Continue topping up fluids appropriately.
Immediately Before the Race
At the conclusion of your warm-up, there’s an opportunity for a small final top-up.
That might include some water and a gel.
Then during the race, I typically recommend taking a gel approximately every 20–30 minutes.
Exactly what works best will vary between athletes.
That’s why you practise it.
Your long runs and appropriate quality sessions aren’t only opportunities to train your legs.
They’re opportunities to train your race-day routine.
Nothing new on race day.
How to Taper for a Half Marathon
You’ve done the training.
Now you need to allow that fitness to appear on race day.
For most half marathon runners, I use approximately a two-week taper.
The objective isn’t to suddenly stop training.
We want to reduce accumulated fatigue while retaining the fitness and movement qualities you’ve spent months developing.
Training volume comes down, but we can retain appropriate frequency and some intensity.
You should arrive at the start line feeling fresher, not feeling as though you’ve spent two weeks doing nothing.
What If You Have Two Races Close Together?
This requires a little more thought.
If you’ve got two important races only two weeks apart, you may complete a normal taper into the first event and then predominantly easy training between races.
If they’re four, five or six weeks apart, we have more options.
We might:
Taper → Race → Recover → Train → Reduced taper → Race
Or, if the second event is the real priority:
Reduced taper → Race → Recover → Train → Full two-week taper → Priority race
Again, periodisation is about looking at the whole season rather than treating every race independently.
How Should You Pace Your Half Marathon?
You’ve trained for months.
Don’t throw all of that preparation away in the opening few kilometres.
One of the most common half marathon mistakes is starting too fast.
Fresh legs, a taper, adrenaline and runners streaming past you can make an unsustainable pace feel surprisingly comfortable.
The consequences often don’t arrive until much later.
That’s why I teach a simple one-third, one-third, one-third strategy:
0–7 km: Control
Run approximately 10–15 seconds per kilometre slower than target goal pace.
Let people go.
You’re not racing them yet.
7–14 km: Settle
Move smoothly onto your target goal pace.
Don’t surge to make up the time you deliberately didn’t spend in the opening seven kilometres.
Settle into your rhythm.
14–21.1 km: Race
Now you’ve earned the right to race.
If you’re feeling good, begin increasing your pace, initially aiming for approximately 10–15 seconds per kilometre faster than goal pace.
Continue reassessing as the finish approaches.
With 5 km remaining, perhaps there’s more available.
At 3 km, reassess again.
And when you’re close enough to the finish?
Use what’s left.
Control. Settle. Race.
I’ve explained the complete strategy here:
Practise Your Race Before Race Day
Race-day execution should feel familiar.
That doesn’t mean completing a half marathon time trial every few weeks.
It means practising the individual components.
Use your long runs to practise fuelling.
Use progressive long runs to practise running faster when you’re tired.
Use tempo sessions to become comfortable at Level III.
Use your 5 km testing to assess fitness.
Practise your breakfast before important long runs.
Use the shoes, socks and clothing you intend to race in.
Learn how your stomach responds to gels.
Learn what your target pace feels like.
The fewer unknowns you take onto the start line, the easier race morning becomes.
Your First Half Marathon Is Different
If this is your first half marathon, don’t feel pressured to approach the event like someone chasing a 75-minute finish.
Your first goal should usually be:
Finish the event and gain experience.
Your first completed half marathon is automatically a personal best.
You’ll learn an enormous amount from those 21.1 kilometres.
You’ll learn about pacing.
You’ll learn about fuelling.
You’ll learn how your body responds after 15, 18 and 20 kilometres.
You’ll learn what you’d do differently next time.
And if you’ve controlled the first two-thirds of the race and feel fantastic with 7 km remaining?
Great.
Start racing.
Experienced Runners Need to Earn More Training
As your performance goals increase, the training can become more sophisticated.
You may run five or six days each week.
You may include a second quality session.
Progressive long runs may feature more regularly.
Race-specific tempo work becomes increasingly important.
You might complete additional Level V work during Final Quality.
But there’s an important principle here:
More advanced training should be earned through your ability to absorb the training you’re already doing.
A sub-90-minute runner may need a substantially different programme from a first-time half marathon runner.
That doesn’t mean copying the sub-90-minute runner’s programme will turn you into one.
Develop the fitness first.
Then allow the training to progress with you.
The Complete Half Marathon Training Picture
When you strip away all the individual workouts, gadgets and numbers, successful half marathon preparation is built on some fairly simple principles.
Start from where you are.
Give yourself enough time.
Run at least three times per week, with four or five being appropriate for many dedicated half marathon runners.
Keep most of your running at Level II.
Develop your long run progressively, generally keeping it to approximately two hours or less.
Introduce the right quality training at the right stage:
Foundation & Injury Prevention → Early Quality → Transition Quality → Final Quality
Use 5 km testing and recent race performances to monitor fitness and establish realistic goals.
Strength train when it genuinely adds value.
Use cross-training appropriately.
Include flexibility and recovery.
Practise your fuelling.
Don’t cram missed training into the next few days.
Taper.
And when race day arrives:
Control. Settle. Race.
None of those individual pieces is particularly magical.
The magic, if there is any, comes from putting them together consistently over enough time.
Ready to Put Your Half Marathon Training Together?
Knowing the principles is one thing.
Putting your Level II running, long runs, quality sessions, recovery, flexibility training, testing, taper and race preparation together in the right order is another.
That’s exactly what structured training is designed to do.
NZ Half Marathon Hub+ gives you access to structured half marathon training plans designed around the same principles I’ve explained throughout this guide.
Whether you’re preparing for your first half marathon or chasing a faster performance, you can choose a programme appropriate to your experience, available preparation time and goal.
Instead of wondering what you should do tomorrow, you can concentrate on completing the training and building towards race day.
👉 Join NZ Half Marathon Hub+ and Start Training
Not Sure What Training Is Right for You?
Sometimes the hardest part isn’t doing the training.
It’s working out which training is appropriate for you.
If you’re unsure about your current fitness, how many days you should train, what programme to choose or whether your goal is realistic, you’re welcome to book a free 40-minute consultation with me.
We’ll talk through where your running is now, where you’d like it to go and what might be the most appropriate way to get there.
👉 Book a Free 40-Minute Consultation with Coach Ray
Train consistently. Recover properly. Arrive prepared. Then give yourself the opportunity to race your best half marathon.
