Naoki (石塚直樹) Ishizuka
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Born : 1966
Cat. M60 Ultrarunner since 2012
36
DUV-index ?Largest integer N such that the runner has at least N credited races of at least N km.
50
DUV-index+ ?Largest integer N such that the race distances provide at least N complete segments of N km in total. A single long race may therefore contribute several segments. See the DUV-Index tab for the detailed calculation. calculation details
1
Countries visited ?Japan
Japan14,1%
Rank quotient ?This runner's calculation uses 36 eligible race(s): Σ(rank − 1) = 5 129; Σ finishers = 36 461. 5 129 / 36 461 × 100 = 14.07%. A win adds 0 to the numerator. Lower is better.
Totals
Ultras completed36
Km — ultra races3 806 km
> 100 km3
> 160 km2
> 200 km1
Longest race225,0 km
14th Gunma 100km Walk — 10/5/2025
Km per year (ultra races)
2022
2023
2024
2025
2026
Race types (share of distance)
Road69,0%
Trail18,4%
Ult.Walk12,6%
Records
HISTORY
36 race(s)| Runner | Races in common |
|---|---|