The quick answer
- 0–3km: Get up to goal pace without overreacting to the crowd. Let your breathing settle and avoid banking time.
- 3–8km: Establish a controlled rhythm. Use the overall effort, not the watch alone, especially on hills and windy stretches.
- 8–15km: Protect the pace through the mentally demanding middle. Take fuel or fluid according to what you practised, and avoid unnecessary surges.
- 15–19km: Reassess honestly. If you still feel in control, begin increasing commitment gradually.
- 19km–finish: Commit with what remains. Keep posture and cadence purposeful, then accelerate only if you genuinely can.
Race strategy
Should you run even or negative splits?
For a relatively flat half marathon, a broadly even-pace plan is a practical starting point when chasing a personal best. A small negative split can work when you've judged the target accurately, but deliberately losing substantial time early may also compromise your finish. Think controlled first kilometres, consistent middle, competitive finish rather than an inflexible split formula.
Five sections, one controlled race plan
Don't win the first kilometre.
Adrenaline can make a pace well beyond your fitness feel effortless. Build into your target pace, find clear running room, and avoid weaving through groups. An opening kilometre slightly off the exact target isn't a crisis; a sustained over-fast start can be.
Cue: “Relax, settle, don't chase.”Find your rhythm.
Work towards consistent effort. Keep your shoulders loose, your stride natural and your mind calm. Use course markers as well as GPS, which can be noisy in crowded urban races. On climbs or into headwinds, protect effort rather than forcing an exact split.
Cue: “Smooth is fast.”Race the middle honestly.
This is often where concentration slips: you are well beyond the start, but the finish still feels distant. Break the section into 2–3km checkpoints. Follow your practised hydration/carbohydrate plan when appropriate for your duration and conditions.
Cue: “One checkpoint at a time.”Increase commitment—not panic.
Make a deliberate assessment of breathing, form and remaining energy. If you've paced accurately, try lifting the effort gradually; if struggling, focus on limiting the slowdown instead of forcing an unsustainable sprint.
Cue: “Build pressure.”Finish the work.
Keep looking ahead, use your arms and stay purposeful through the final turns. In the last kilometre, commit to whatever faster pace you can sustain without losing form. A strong finish is earned by the decisions you made earlier.
Cue: “Commit, then empty the tank.”Example: breaking 1:30 in the half marathon
A target of 1:29:30 requires approximately 4:14.5/km or 6:49.6/mile over the full 21.0975km. Start at a sustainable rhythm rather than chasing a large cushion in the first few kilometres.
| Section | Segment | Elapsed | Race cue |
|---|---|---|---|
| 5 km | 21:13 | 21:13 | Stay on your planned effort |
| 10 km | 21:13 | 42:25 | Stay on your planned effort |
| 15 km | 21:13 | 1:03:38 | Stay on your planned effort |
| 20 km | 21:13 | 1:24:51 | Stay on your planned effort |
| 21.0975 km | 4:39 | 1:29:30 | Finish |
The table is an even-pace benchmark, rounded to the nearest second. On hills or in heat, prioritise controlled effort rather than hitting every split rigidly.
Fueling, terrain and weather
Fuel according to race duration, not simply distance. A runner finishing near an hour has different needs from someone racing for two hours or longer. For events lasting around 1–2.5 hours, sports nutrition guidance commonly discusses approximately 30–60g of carbohydrate per hour, provided it is practised and tolerated. This is general guidance, not an instruction to take fuel you have never tried in training. [5]
In hot conditions, lower your opening effort and use conditions—not an idealised pace chart—to guide adjustments. On a hilly route, match effort on the climbs and regain rhythm gradually on flatter sections rather than forcing every kilometre to be identical.
Research & lessons from elite racing
A 2024 systematic review covering 39 studies found that half-marathon participants generally demonstrated less pacing variation than full-marathon runners. A 2026 narrative review drawing on 37 studies also reported generally more even pacing in half marathons than marathons. These are observational findings: they describe what runners have done, and do not establish one optimal pacing pattern for everyone. [1, 2]
What the evidence says
Half marathons are generally more evenly paced than marathons. A 2024 systematic review reported greater pacing variability and more slowing over the full marathon than over the half marathon. A 2026 synthesis reached a similar conclusion across performance levels, although the observational evidence has limitations. [1, 2]
A 2026 systematic review and network meta-analysis of experimental endurance studies found no clear overall performance advantage for one imposed pacing strategy over self-selected pacing across its included events. This isn't half-marathon-specific evidence, but reinforces the need to avoid claiming one precise split pattern is scientifically best for everyone. [3]
What an elite race can teach us
At the 2026 Lisbon Half Marathon, Jacob Kiplimo ran a World Athletics-recognised world record of 57:20. He and a rival reached 15km in 40:52, then Kiplimo ran the next 5km in 13:31 and pushed on towards the finish. This is a documented example of late-race commitment at elite level, not a pacing target to copy directly. [4]
From the World Athletics Lisbon race report. The 15–20km split is quicker than the 15km average pace. That illustrates how a well-conditioned elite runner can increase pressure late in a race.
Visualise what a too-fast start can cost
This original model compares two illustrative pacing distributions that total the same finish time. The more aggressive plan must slow later to compensate. It is a mathematical scenario—not published athlete data or a prediction that every runner will fade.
Bars show segment seconds per kilometre; taller means slower. Final 1.0975km is also modelled in the total race time but omitted from these equal-length columns.
Common mistakes & how to avoid them
Starting at 10K effort
Better approach: Settle into a sustainable half-marathon rhythm across the opening kilometres.
Waiting until exhausted to fuel
Better approach: Practise a plan in training and follow it early where appropriate.
Forcing identical splits on hills
Better approach: Prioritise effort and course markers over GPS pace spikes.
Drifting through the middle kilometres
Better approach: Break the race into smaller checkpoints and protect attention through 10–18km.
Questions runners ask
Quick answers to common questions about pacing a Half Marathon race.
Should I aim for even or negative splits?
Broadly even pacing is a straightforward starting point for a flat course and a realistic target. A modest negative split can be sensible if you're feeling controlled, but neither strategy guarantees the fastest outcome.
What pace is a 1:45 half marathon?
Approximately 4:59 per kilometre or 8:00 per mile. The interactive planner above calculates precise checkpoints using 21.0975km.
Should I sprint at 15km?
Usually not all-out. Gradually increase effort if you're feeling strong, then commit more decisively in the last kilometres.
Do I need gels in a half marathon?
That depends on duration, nutrition before the race and individual tolerance. Practise any fueling plan in training; avoid trying unfamiliar products on race day.
Calculate your own pace & splits
Choose a goal time and compare even pacing, a controlled faster or slower second half, and an elite race pattern scaled to your own target.
These are proportional split times adapted to your selected target. See source race.
Target split checkpoints
Even-pace reference| Section | Split | Elapsed |
|---|---|---|
| 5km | 21:20 | 21:20 |
| 10km | 21:20 | 42:40 |
| 15km | 21:20 | 1:03:59 |
| 20km | 21:20 | 1:25:19 |
| Finish · 21.0975km | 4:41 | 1:30:00 |
Strategies are illustrative and always total your chosen finish time. The relative pacing of an elite athlete is not necessarily optimal for you; adjust for terrain, tactics and fitness.
Paces are calculated from the full official race distance. The race plan can be adjusted in Split Calculator.
References & further reading
- Sha et al. (2024), Pacing strategies in marathons: A systematic review. Review including half- and full-marathon pacing comparisons.
- Pacing Profiles in Half-Marathon and Marathon Running Based on Performance Level, Sex, and Age (2026). Narrative review of 37 studies through March 2026.
- Comparative Effects of Pacing Strategies on Endurance Performance (2026). Cross-sport experimental systematic review; not specific to the half marathon.
- World Athletics (2026): Kiplimo breaks world half marathon record in Lisbon. Official race report with 15km and 15–20km split details.
- Thomas, Erdman & Burke (2016), Nutrition and Athletic Performance. Joint position statement on sports nutrition.
Selectable elite model reference: Official or published elite race timings. The timing profile is scaled, not a promise of performance.