Guide

Marathon and half marathon pacing on Apple Watch: how to actually hold your goal time

Most marathon goal times are lost in the first 5 km, when the legs are fresh, the crowd is loud and 10 seconds a kilometre feels like nothing. The fix is not willpower; it is a plan that lives on your wrist and tells you, split by split, whether you are on it. Here is how to build that plan for a marathon or half marathon on Apple Watch, and how to run it.

Vanoor's race pacing planner on iPhone: distance, goal time and the split curve
The planGoal time in, a split curve you can shape.
Vanoor's pacer screen on Apple Watch: the target band, live pace and seconds ahead of plan
Race dayLive pace against the band, seconds ahead or behind.

Step 1 — Pick a goal you have earned

A realistic marathon goal is roughly your recent half marathon time × 2.1 (× 2.08 if you are well trained for the distance, × 2.15 if it is your first). For a half, take a recent 10K × 2.2. If you have no recent race, run 3 × 3 km at goal pace with 2 minutes' rest two weeks out; if it felt "comfortably hard", the goal is honest.

Step 2 — Shape the splits

For both distances, plan a gentle negative split: first kilometres 5–8 s/km slower than average pace, last kilometres 5–8 s/km faster. On a hilly course plan by effort instead — slower kilometres uphill, faster down — so the plan is even in effort, not in numbers. Use the negative split calculator to get the kilometre table, or build it directly in Vanoor: My Workouts → + → Race Pacing Strategy, choose the distance and goal time, drag the curve, done. The planner keeps the total time fixed however you shape it.

Step 3 — Add the cues that save races

What race day looks like on the wrist

During the run the Watch shows the split you are in, the pace band for it (target ±15 s/km), your live pace inside it — green in, red out — and the distance left in the split. A heads-up buzz precedes every change of pace and the next split's card announces the new target. You never need to do arithmetic at 35 km.

When the plan slips

Half marathon specifics

The half is short enough that fuel is rarely the limiter and long enough that a fast start still hurts. Keep the spread small (5–8 s/km), take one gel around 50 minutes if the race is over 1:40, and plan the last 3 km as a single "go" split.

The rule: the plan's job is to stop you doing anything rash in the first ten minutes. If it does that, the second half takes care of itself.

Last checked 18 September 2026.

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