Where do improving runners find time?
Improvement is more revealing when you can see where it appeared. Compare faster races with the same runners’ earlier bests.
What the data shows
Improving finishes in 3:52:30–4:07:30 gained 19.9 minutes on average versus an earlier recorded best: from 4:19:03 to 3:59:12.
The three block gains add to the mean total improvement. Negative means the improving runners were, on average, slower in that block despite a faster overall finish.
All courses · all ages · all recorded categories · all earlier-time bands. 34,519 finishes across 155 race editions.
Explore the comparison
Where the mean finish improvement came from
Minutes
View exact values and sample sizes
| Group | Where the mean finish improvement came from | Observations |
|---|---|---|
| Opening 6.21 mi | 2.8 min | 34,519 |
| Middle 12.43 mi | 8.3 min | 34,519 |
| Final 7.58 mi | 8.8 min | 34,519 |
How to read this
Positive values are minutes gained in each part of the race. The three parts add up to the average improvement.
Keep in mind
An earlier recorded best may not be a lifetime personal best. The comparison includes runners whose histories could be linked.
How we calculated this
Select finishes in the displayed achieved-time band that beat the runner’s fastest recorded finish from strictly earlier years. Compare durations in the opening 6.21 mi, middle 12.43 mi and final 7.58 mi with that earlier result. Mean block gains sum to mean finish improvement. This is an earlier recorded best, not a lifetime personal best or a prescription for a future improvement.
Runner comparison groups contain at least 100 eligible observations. Broader comparisons are labeled; a finish can belong to a runner with several races. Elevation describes the supplied course profile.
We check the raw timings and apply reviewed source-quality rules before forming these groups. Editions with known invalid split grids, incomplete ingestion, unresolved source checks or a selected field are excluded. Missing age or recorded gender alone does not remove an otherwise eligible finish from the overall comparison.
Input data: Marathon results, weather and course data. Read the full methods in source units or browse the marathons, years and data fields.