Analyses

Each one answers a pacing question, then lets you set it to your course and time.

The first 5K
1. Starting pace5 minutes 5 secondsbehind same-pace runners at the finish, after a first 5K over 10% fast
2. Downhill starts16 percentof finishes opened over 5% fast, with or without a downhill start
The shape of a race
1. Your pacing pattern40 seconds a mileslower than even pace at 35–⁠40K, for finishes near 4:00
Halfway to 30K
1. From a checkpoint13 percentof finishes on even 4:00 pace at 30K still got under 4:00
After 30K
1. The minutes that matter66 percentof the 4:51 between finishes just under and just over 4:00 opened after 20K
The finish line
1. Your target in context5 percentof finishes were under 3:00, against 42% under 4:00
Who holds pace
1. Age and pace7 to 8 percentslower over the second 20K than the first, in every age group near 4:00
Where you run
1. Compare the courses20 to 46 percentsustained slowdown, course by course
2. Hills and pacing4 percentslower than the same 5K elsewhere, on Boston’s 30–⁠35K climb
The weather
1. Race-day weather41–50 degrees Fahrenheitthe start temperature with the fewest sustained slowdowns
The next one
1. Where runners improve43 percentof the minutes improving finishes gained came after 30K