Pace strategy calculator (segment-by-segment pacing)
Split your race course, set the elevation per segment, and get an optimised pace plan for your goal time. TCX export for Garmin, COROS, and Suunto.
Race parameters
How does the pace strategy work?
The principle is simple: instead of running at a constant pace (which takes a lot more effort uphill than downhill), you adjust pace segment by segment to keep effort constant. The result is often a better finish time, and a much more controlled race.
The tool uses a model based on the energetic cost of grade: each 1% of climb adds about 6 to 8 seconds per kilometre, and each 1% of descent removes around 3 to 4 seconds. This asymmetric ratio reflects the fact that going downhill is not as "free" as going uphill is costly.
The negative split: the gold standard for racing
A negative split means running the second half of your race faster than the first. Almost every world record, including Sabastian Sawe's recent sub-2h marathon, was set this way. The reason is physiological: at the start, you have full glycogen stores and a fresh body, but going out too fast burns them faster than necessary. By holding back early, you keep something in reserve for the final third, when most runners are slowing down.
For a flat course, target a negative split of 30 to 90 seconds (half marathon) or 1 to 3 minutes (marathon) between the two halves. For a course with elevation, the segment-by-segment plan above already builds in the right effort distribution: you don't need to fight the hills, you adapt to them.
When to use a pace strategy
Going out too fast on these distances always costs you. A segment-by-segment plan protects against the "wall" at km 30. Pre-set strategy is also what most sub-3h marathoners use to stay disciplined under race-day adrenaline.
A 10K with 200m of elevation gain doesn't run like a flat 10K. The tool calculates exactly how much to slow down on climbs and accelerate on descents to hold target time.
With marked elevation profiles, pace management becomes even more critical. Every poorly managed climb costs you in the final kilometres. Every badly negotiated descent shreds quads you won't get back.
Whether you're chasing sub-50 on the 10K, a Boston Qualifier, or sub-3h marathon, a precise pace plan is your best friend on race day.
Frequently asked questions
What is a pace strategy in running?
A pace strategy is a plan that splits your race course into segments and assigns a target pace to each, taking elevation into account. The goal is to distribute effort optimally so you avoid going out too fast and falling apart in the second half.
Why adjust pace based on elevation?
Holding the same pace uphill and on the flat takes much more energy on climbs. A good strategy is to slow down on uphills to preserve energy, then claw back time on the descents. Perceived effort stays constant, and your finish time is often better than trying to run a flat-pace strategy on hilly terrain.
How do you define your race segments?
Split your course into homogeneous chunks: a flat segment, a climb, a descent, etc. Each segment should have a relatively constant elevation profile. As a rule of thumb, segments of 1 to 5 km work well.
Should you accelerate on descents?
Yes, moderately. Gravity helps and muscular effort decreases. You can gain a few seconds per kilometre without spending more energy. Watch out for steep descents, though, they hammer the quadriceps.
How do you use a pace strategy on race day?
Program your target paces per segment on your GPS watch (TCX export below) or write them on a wristband. The idea is to remove decisions during the race: you just follow the plan segment by segment.
What is a negative split strategy?
A negative split means running the second half of the race faster than the first. Most world records, including the recent sub-2h marathon, were set this way. It works because you start with full glycogen stores and a fresh body. Going out too fast (positive split) is the most common mistake in distance running.
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Plan your race strategy segment by segment and finish strong.