If your half marathon starts feeling hard in the first few kilometres, there’s a good chance you’ve already made your biggest pacing mistake.
The best half marathons aren’t raced by trying to bank time early. They’re raced by having the patience to start smart, the discipline to settle in, and enough left to finish strong.
A half marathon is long enough that an overly ambitious opening can come back to haunt you, but short enough that you can genuinely race the closing kilometres if you manage your effort correctly.
One of my favourite ways to approach the 21.1km distance is to divide it into three roughly equal sections:
0–7km: Start Smart
7–14km: Settle In
14–21.1km: Finish Strong
Each section has a different job. Get them right and, rather than desperately hanging on over the final few kilometres, you can be the runner who is still moving strongly and passing people.
Why Half Marathon Pacing Matters
One of the dangers of starting too quickly is that you often don’t experience the consequences immediately.
Run your opening kilometre 10 or 15 seconds faster than planned and you might feel fantastic. You may still feel fantastic at 5km.
That can reinforce the mistake.
Maybe today’s my day. Maybe I can hold this.
Unfortunately, you’ve increased the physiological cost of those early kilometres, and eventually that bill needs to be paid. That’s why I don’t like the idea of banking time. You aren’t really putting time into the bank—you’re borrowing it, and the interest rate can be severe.
A well-paced half marathon should almost feel suspiciously comfortable early.
By the closing kilometres, maintaining exactly the same pace may feel extremely challenging. That doesn’t necessarily mean you’ve paced poorly. As fatigue accumulates, the effort required to maintain your pace increases.
The goal isn’t to make the first 5km impressive.
The goal is to put yourself in a position to race the final 5km.
Know What You’re Capable of Before Race Day
Smart pacing starts before you reach the start line.
You need to separate the half marathon time you’d like to run from the performance your current fitness suggests you’re capable of.
Look at your recent training. Look at recent races. Consider the quality sessions you’ve completed. What evidence do you actually have to support your goal?
From there, establish a target finishing time and approximately what average pace that requires.
I also like athletes to have more than one goal.
An A goal might represent what you’re capable of when everything goes particularly well. Your B goal can represent a strong, realistic performance. A C goal gives you something meaningful to work towards when the conditions, course or your body aren’t giving you the perfect day.
Remember that your goal also needs to reflect the race you’re actually doing.
A flat half marathon on a cool, still morning isn’t equivalent to a hilly course on a hot or windy day. Your watch might display the same pace, but your body certainly doesn’t experience the same effort.
0–7km: Start Smart
This is potentially the most important third of your race.
Your job is simple:
Be controlled. Be patient. Be disciplined.
Don’t worry if people are passing you. Don’t panic when someone you normally beat disappears up the road. And don’t become concerned if your planned race pace feels surprisingly easy.
That’s what we want.
Depending on congestion at the start, your opening kilometre may even be slightly slower than planned. That’s okay. Don’t immediately accelerate during kilometre two to recover those lost seconds.
Settle naturally into the race.
You’re not trying to win the first 7km. You’re trying to get through those kilometres using as little unnecessary energy as possible while remaining in touch with the performance you’re targeting.
For an athlete targeting a particular average race pace, I will sometimes have them run this opening third around 10–15 seconds per kilometre slower than their target pace. The exact numbers will depend on the athlete and race, but the principle remains the same: deliberately hold something back.
7–14km: Settle In
The excitement of the start should now have disappeared. The field has spread out and you should have found your rhythm.
This is where I want you to become almost boringly consistent.
Gradually settle onto your planned race pace. Monitor the numbers on your watch, but also pay attention to how that pace feels.
Keep on top of your fuelling and hydration rather than waiting until you’re thirsty or running low on energy before doing something about it.
Most importantly, remain patient.
You may reach 10 or 12km feeling fantastic and be tempted to start pushing. I’d still encourage patience.
Get yourself to 14km in good shape.
You’ve now completed approximately two-thirds of the race—and things are about to become interesting.
14–21.1km: Finish Strong
Now you can start asking different questions.
How am I feeling?
Is this pace still sustainable?
Have I got something more available?
If the answers are positive, gradually increase your effort.
Notice that I said effort, not necessarily pace.
Even maintaining your existing pace late in a half marathon can require a significant increase in effort as fatigue accumulates. But if you’re feeling strong, this is where you can start racing the people around you.
Pick somebody ahead.
Gradually work towards them.
Pass them, settle again, and find the next person.
That can be mentally much easier than continually telling yourself, I’ve still got six kilometres to go.
As the finish gets closer, the risk associated with increasing your effort becomes progressively smaller.
At 16km, remain sensible.
At 18km, you can start committing.
At 20km, if you’ve got something left, use it.
The ideal scenario is to cross the finish line knowing there wasn’t another kilometre available at that effort.
Should You Run a Negative Split?
This three-part approach effectively creates a controlled negative-split strategy.
Rather than attempting to hold exactly the same pace from start to finish, an example might look like this:
First 7km: approximately 10–15 seconds/km slower than target pace.
Middle 7km: around target race pace.
Final 7.1km: gradually increase towards approximately 10–15 seconds/km faster if you’re capable of doing so.
Across the entire race, those sections can balance each other out while giving you a much greater chance of finishing strongly.
Those numbers aren’t a rigid formula for every athlete or every course. What matters most is the progression: controlled early, race pace through the middle, stronger late.
Pace Versus Effort
No pacing plan survives every race perfectly.
The course could be hillier than expected. You might encounter a strong headwind. The temperature could be considerably warmer than forecast. Or you may simply wake up on race morning and discover your body isn’t giving you what you expected.
This is where you need to distinguish pace from effort.
Suppose your goal is 5:00/km and you’re climbing a hill into a headwind. Insisting on maintaining 5:00/km could be a terrible pacing decision.
Allow your pace to slow while keeping your effort appropriate.
The same applies when your body is telling you something isn’t right.
If you’re at 5km and your planned race pace already feels like something you’d normally expect at 17km, pay attention to that information.
Adjusting your target early might cost you a minute or two.
Refusing to adjust could cost you ten.
Changing the plan isn’t giving up. Sometimes it’s the smartest racing decision you can make.
What About Half Marathon Pace Groups?
Pace groups can be useful, but don’t automatically assume the pacer will use the same strategy you intend to use.
Some races instruct their pacers to run even splits. Others may approach pacing differently, and individual pacers can vary.
From my own experience pacing marathons, we were instructed to maintain even splits. That meant an athlete wanting a negative split could initially run with us and then move ahead later.
If you know you’re someone who gets carried away at the start, there can even be value in beginning with the pace group behind your target group. Let them help keep you under control during the opening kilometres, then gradually increase your pace.
Ideally, you’ll eventually catch your target pace group—and potentially continue past them.
Just remember that a pacer is a useful tool, not a substitute for understanding your own race plan.
What If the Half Marathon Isn’t Your Only Event?
The same principles can still work when a half marathon forms part of a multi-event challenge, but your overall target needs to become more conservative.
During the Group Coaching Call, one athlete asked about completing a half marathon followed by two further runs that day and another run the following morning.
My recommendation was still to aim for a strong finish—but to make the overall half-marathon goal substantially more conservative than it would be for a standalone race.
The objective changes.
You’re no longer trying to extract your absolute best half-marathon performance. You’re pacing the half marathon as one component of a much bigger endurance challenge.
Can You Use This Strategy for Other Race Distances?
Yes.
The Start Smart → Settle In → Finish Strong concept can be adapted to other distances, including the marathon.
Even in a 5km race, you can think in thirds: establish yourself during the opening section, settle into your race through the middle, then progressively commit during the final third—particularly over the closing kilometre.
The specifics change with the distance, terrain, athlete and event.
The underlying principle doesn’t:
Don’t spend energy early that you’re going to desperately need later.
Your Half Marathon Pacing Plan
When you’re standing on the start line of your next half marathon, don’t overload yourself with complicated instructions.
Give yourself three jobs:
0–7km — Start Smart
Be patient, controlled and disciplined.
7–14km — Settle In
Find your rhythm, move towards your race pace and protect the race you’ve set up.
14–21.1km — Finish Strong
Progressively increase your effort and transition from pacing yourself to racing.
The goal isn’t to feel fantastic at 5km.
The goal is to be able to race the final 5km.
If you’re flying at 5km but walking at 19km, those fast opening kilometres haven’t helped you.
But if you reach 16 or 17km and start passing runners who disappeared up the road earlier, that’s a completely different experience.
You’ve paced the race instead of allowing the race to pace you.
Want Help Planning Your Next Half Marathon?
Not sure what pace you should target, how to approach a hilly course, or whether your goal time matches your current fitness?
We can work through your recent training, race goals and upcoming event and develop a pacing approach appropriate for you, rather than relying on a generic race-day formula.
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Whatever your goal for your next half marathon, remember:
Don’t try to win the race in the opening kilometres. Start Smart. Settle In. Give yourself the opportunity to Finish Strong.