| Difficult Run to Orthez | 3,849.78 mi (6,195.63 km) |
| Difficult Run to Orvault | 3,712.77 mi (5,975.13 km) |
| Difficult Run to Osny | 3,826.56 mi (6,158.26 km) |
| Difficult Run to Ostwald | 4,076.41 mi (6,560.35 km) |
| Difficult Run to Ouistreham | 3,723.19 mi (5,991.90 km) |
| Difficult Run to Oullins | 4,036.27 mi (6,495.75 km) |
| Difficult Run to Outreau | 3,766.43 mi (6,061.48 km) |
| Difficult Run to Oyonnax | 4,057.11 mi (6,529.28 km) |
| Difficult Run to Ozoir-la-Ferriere | 3,859.82 mi (6,211.79 km) |
| Difficult Run to Pace | 3,685.11 mi (5,930.61 km) |
| Difficult Run to Palaiseau | 3,843.14 mi (6,184.93 km) |
| Difficult Run to Pamiers | 3,969.48 mi (6,388.26 km) |
| Difficult Run to Panazol | 3,879.02 mi (6,242.67 km) |
| Difficult Run to Pantin | 3,845.02 mi (6,187.96 km) |
| Difficult Run to Paray-le-Monial | 3,984.98 mi (6,413.20 km) |
