Data
100 ultra runners: how many keep coming back?
The numbers behind those who run ultra after ultra.
5 min read
If you have run an ultramarathon, you probably started with a 50 km race. The nerves were probably part of the training. They kept you awake the night before the race and stayed with you at least until you actually started running. You probably gave it a great effort and finished thinking it was one of the hardest challenges you have ever conquered. After you crossed the finish line, you were probably wondering how some people can run double or triple that distance. What I am not sure about is how likely it is that you did it all again.
1 ultra
100 out of 100 remain (100%)
When you finished that first ultra, you became one of about 2.6 million people in the world to do it. That is equivalent to just 0.031% of the world's population. To put it in perspective, it is about the number of people living in Brooklyn, New York.
2 ultras
54 out of 100 remain (54.18%)
If we randomly pick 100 of those 2.6 million runners, almost 54% come back for a second one, after a median time of almost exactly a year. If we wait 3 years after that first race, the share goes up to 60%.
3 ultras
37 out of 100 remain (37.181%)
Fewer than half of the runners come back for a third ultra: only 37 out of 100. The median time between the second and the third is now under 300 days.
4 ultras
28 out of 100 remain (27.923%)
By the fourth ultra, we lose another 9 runners. Things change a little after this fourth one. My fourth official ultra was quite important for me: it was my first 100 km race, Mozart 100, at a time when I was hungry to keep moving forward.
5 ultras
22 out of 100 remain (22.132%)
22% of these athletes run 5 ultras. The median time between the fourth and the fifth is just over 200 days. These runners are now hooked.
6 ultras
18 out of 100 remain (18.328%)
From here on, the drop starts slowing down. 18 out of 100 ultra runners have finished 6 ultras, and the median time between these races is down to 259 days. These runners start more than one of these events a year.
7 ultras
15 out of 100 remain (15.199%)
Three fewer runners by the seventh ultra. My sixth ultra was TDS, a brutal race that took me more than 35 hours to finish and left me physically and mentally exhausted. It was the first time I thought about stopping for a while. Even so, 10 months later I was back at the start line of a 100 km race.
8 ultras
13 out of 100 remain (12.931%)
At the eighth ultra we lose two more runners. Segmenting by age, runners who run their first ultra between 30 and 50 years old are the most likely to come back for a second, at about 64%.
9 ultras
11 out of 100 remain (11.281%)
Two fewer runners again. In the 50 to 60 years old group and among those under 30, 58% come back for a second ultra. Among runners over 60, it is 54%.
10 ultras
10 out of 100 remain (9.842%)
Runners who reach 10 ultras seem truly in love with the sport. We can see it because fewer and fewer of them stop. How many ultras do you think you could run in a year?
11 ultras
9 out of 100 remain (8.547%)
When an ultra runner goes beyond 10 ultras, their median time between these races is only 175 days: two or more races longer than 42 kilometers a year. This is my current number. If you read my previous article, you know that my eleventh ultra left me extremely tired, drained, and even injured, but I love this sport, so see you at number 12.
12 ultras
8 out of 100 remain (7.559%)
14% of ultra runners between 30 and 50 years old reach the 10-ultra mark. One step below are the groups between 50 and 60 years old and those under 30, at around 10%. Among those over 60, 5% reach 10 ultras.
13 ultras
7 out of 100 remain (6.754%)
When we look at the numbers by gender, the gap in participation is clear, but the percentage of women and men who keep running ultra after ultra is not that different. 49 out of 100 women and 56 out of 100 men who finish their first ultra decide to come back for a second one.
14 ultras
6 out of 100 remain (5.99%)
By 10 ultras, the difference gets smaller: 8% of women reach that mark, compared with 10% of men. This is one more sign that women thrive in this sport, and that we need to encourage and support the growth of their participation.
15 ultras
5 out of 100 remain (5.392%)
From 15 ultramarathons on, fewer than 1% decide not to continue. Between ultra 14 and 15, the median time is just 104 days, which means these runners are already planning to take part in 3 or 4 ultras a year.
16 to 19 ultras
5 out of 100 remain (4.84%)
How many ultramarathons until only one in every 100 runners is still going?
20 to 23 ultras
3 out of 100 remain (3.289%)
Runners who reach 20 ultramarathons, on average, are used to running one of these extremely hard races every 100 days.
24 to 29 ultras
2 out of 100 remain (2.328%)
At ultra 24, only 2 runners out of every 100 remain. And these runners will most likely finish at least 5 more ultramarathons.
30 ultras
1 out of 100 remain (1.466%)
Only one out of every 100 ultra runners finishes 30 ultras. Do you think you will be one of them? That translates to fewer than 38,000 people in the whole world. For reference, that is fewer than the population of the Greenpoint neighbourhood in Brooklyn (see map below).
In the whole world, 2.6 million people have finished an ultramarathon.
Women and men
Share of each group that reaches each number of ultras.
- Women
- Men
| ultras | Women | Men |
|---|---|---|
| 1 | 100% | 100% |
| 2 | 49.5% | 55.6% |
| 3 | 32.4% | 38.6% |
| 4 | 23.5% | 29.2% |
| 5 | 18.4% | 23.2% |
| 6 | 15% | 19.3% |
| 7 | 12.6% | 16% |
| 8 | 10.7% | 13.6% |
| 9 | 9.3% | 11.9% |
| 10 | 7.9% | 10.4% |
| 11 | 6.7% | 9.1% |
| 12 | 5.9% | 8.1% |
| 13 | 5.3% | 7.2% |
| 14 | 4.7% | 6.4% |
| 15 | 4.2% | 5.7% |
| 16 | 3.8% | 5.2% |
| 17 | 3.5% | 4.7% |
| 18 | 3.2% | 4.2% |
| 19 | 2.9% | 3.9% |
| 20 | 2.6% | 3.5% |
| 21 | 2.4% | 3.2% |
| 22 | 2.2% | 2.9% |
| 23 | 2% | 2.7% |
| 24 | 1.9% | 2.5% |
| 25 | 1.7% | 2.3% |
| 26 | 1.6% | 2.1% |
| 27 | 1.5% | 2% |
| 28 | 1.4% | 1.8% |
| 29 | 1.3% | 1.7% |
| 30 | 1.2% | 1.5% |
Age at the first ultra
Share of each group that reaches each number of ultras.
- Under 30
- 30–39
- 40–49
- 50–59
- 60 and over
| ultras | Under 30 | 30–39 | 40–49 | 50–59 | 60 and over |
|---|---|---|---|---|---|
| 1 | 100% | 100% | 100% | 100% | 100% |
| 2 | 56.6% | 63.4% | 64.2% | 57.9% | 53.7% |
| 3 | 38.5% | 46.4% | 47% | 40.3% | 34.4% |
| 4 | 28.3% | 36.1% | 36.7% | 30.8% | 23.6% |
| 5 | 22% | 29.2% | 29.7% | 24.9% | 18.4% |
| 6 | 18.2% | 24.6% | 25.1% | 20.2% | 13.4% |
| 7 | 14.7% | 20.8% | 21.1% | 17% | 10.5% |
| 8 | 12.6% | 17.9% | 17.9% | 14.4% | 7.3% |
| 9 | 11.1% | 15.7% | 15.8% | 12.2% | 6% |
| 10 | 9.6% | 13.8% | 13.8% | 10.4% | 5.3% |
| 11 | 8.3% | 12.1% | 12% | 9.1% | 4% |
| 12 | 7.5% | 10.7% | 10.6% | 8% | 3.8% |
| 13 | 6.6% | 9.5% | 9.7% | 7% | 3.1% |
| 14 | 6% | 8.4% | 8.5% | 6% | 2.8% |
| 15 | 5.5% | 7.6% | 7.7% | 5.3% | 2.2% |
| 16 | 5% | 6.8% | 6.9% | 4.8% | 1.9% |
| 17 | 4.5% | 6.2% | 6.3% | 4.3% | 1.7% |
| 18 | 4% | 5.6% | 5.8% | 3.9% | 1.7% |
| 19 | 3.6% | 5.1% | 5.3% | 3.5% | 1.6% |
| 20 | 3.3% | 4.7% | 4.7% | 3.2% | 1.5% |
| 21 | 3% | 4.3% | 4.4% | 2.8% | 1.4% |
| 22 | 2.8% | 3.8% | 4% | 2.6% | 1.2% |
| 23 | 2.6% | 3.5% | 3.6% | 2.4% | 0.8% |
| 24 | 2.5% | 3.2% | 3.4% | 2.2% | 0.8% |
| 25 | 2.3% | 2.9% | 3.2% | 2% | 0.8% |
| 26 | 2.1% | 2.7% | 2.9% | 1.9% | 0.8% |
| 27 | 2% | 2.5% | 2.8% | 1.8% | 0.8% |
| 28 | 1.9% | 2.3% | 2.5% | 1.7% | 0.8% |
| 29 | 1.8% | 2.1% | 2.3% | 1.5% | 0.8% |
| 30 | 1.7% | 1.9% | 2.2% | 1.4% | 0.8% |
The data comes from one of my favourite websites: DUV Ultramarathon Statistics, in October 2026.
Music: 'Lucidity' by Wisanga on #Uppbeat https://uppbeat.io/c/wisanga