Train for 100 km
Long days on your feet, built up from your last finish.
From walking to 100K: 1.5 to 2.5 years, adjusted to you once you start.
How long to train for a 100K
| Goal | From “not moving much” | From “I walk” | From “I run a little” | From “I run a lot” |
|---|---|---|---|---|
| 100K | 1.5 to 2.7 years | 1.5 to 2.5 years | 1.3 to 2.3 years | 11 to 20 months |
The way there
- Walk. 30 minutes of brisk walking, 5 days a week.
- 5K. 5 km without walking.
- 10K. 10 km at an easy pace.
- Half marathon. A 16 to 18 km long run, with no pain the next day.
- Marathon. A 30 to 32 km long run, and a year of steady running.
- 50K. Back-to-back long runs, eating on the move.
- 100K. A 50K finish, and long days on your feet.
You join at the rung you are on today. A rung is passed by doing it, not by the calendar.
The real top of the sport
| Event | Men | Women |
|---|---|---|
| Marathon | 1:59:30, Sabastian Sawe (2026) | 2:09:56, Ruth Chepngetich (2024) |
| 50 km | 2:38:43, CJ Albertson (2022) | 2:59:54, Desiree Linden (2021) |
| 100 km | 6:05:35, Aleksandr Sorokin (2023) | 6:33:11, Tomoe Abe (2000) |
| 100 miles | 10:51:39, Aleksandr Sorokin (2022) | 12:42:40, Camille Herron (2017) |
| 24 hours | 319.6 km, Aleksandr Sorokin (2022) | 278.6 km, Sarah Webster (2025) |
| 48 hours | 485.1 km, Matthieu Bonne (2025) | 436.4 km, Patrycja Bereznowska (2025) |
| 6 days | 1,045.5 km, Matthieu Bonne (2024) | 928.6 km, Stine Rex (2025) |
As of October 2026. Sources: IAU world records, Marathon records, The Running Channel.
Common questions
How long does it take to train for a 100K?
Training for a 100K takes about 11 to 20 months for someone who has run a marathon. The plan expects a 50K finish on the way.
What is the 100 km world record?
The 100 km world records are 6:05:35 for men (Aleksandr Sorokin, 2023) and 6:33:11 for women (Tomoe Abe, 2000), per the IAU as of October 2026.
How much should I eat during a 100K?
Eating during a 100K is trained like running is: practiced on every long run until your gut handles it. The plan builds this into the long days.
Written and checked by the AskDoc Medical Team. How we review. Health education, not medical advice.