| Keyword | CPC | PCC | Volume | Score |
|---|---|---|---|---|
| hardest ultra marathons in the world | 1.2 | 0.9 | 3763 | 80 |
| hardest marathon in the world | 0.63 | 0.7 | 7096 | 12 |
| toughest marathons in the world | 1.26 | 0.9 | 4525 | 62 |
| best ultra marathons in the world | 0.87 | 0.7 | 5639 | 17 |
| hardest marathons in the us | 1.88 | 0.8 | 9491 | 81 |
| best ultra marathoner in the world | 0.61 | 0.2 | 5278 | 95 |
| hardest marathon in uk | 0.49 | 0.3 | 5533 | 73 |
| coolest marathons in the world | 1.04 | 1 | 3480 | 53 |
| toughest marathon in usa | 1.02 | 0.3 | 3904 | 39 |
| craziest ultramarathons in the world | 1.29 | 0.2 | 6251 | 49 |
| best ultra marathons in the usa | 1.36 | 0.7 | 4132 | 50 |
| best ultra marathons in the us | 0.29 | 0.3 | 4056 | 73 |
| most famous ultra marathons | 0.17 | 0.5 | 7705 | 61 |
| considered one of the toughest marathon | 1.71 | 0.5 | 1862 | 91 |
| ultra marathon world record | 0.57 | 0.9 | 8650 | 89 |
| best ultramarathon runners in the world | 2 | 0.4 | 5207 | 31 |
| most beautiful ultra marathons | 0.11 | 0.6 | 3709 | 26 |
| what is the longest ultra marathon | 0.85 | 1 | 7101 | 50 |
| best uk ultra marathons | 0.52 | 0.4 | 3140 | 92 |
| hard rock ultra marathon | 0.44 | 0.6 | 9872 | 46 |
