| Difficult Run to Brownhills | 3,580.59 mi (5,762.40 km) |
| Difficult Run to Broxbourne | 3,676.49 mi (5,916.74 km) |
| Difficult Run to Broxburn | 3,462.45 mi (5,572.27 km) |
| Difficult Run to Bryn | 3,535.40 mi (5,689.68 km) |
| Difficult Run to Buckhurst Hill | 3,681.42 mi (5,924.67 km) |
| Difficult Run to Buckie | 3,455.12 mi (5,560.48 km) |
| Difficult Run to Buckingham | 3,632.11 mi (5,845.32 km) |
| Difficult Run to Buckley | 3,524.38 mi (5,671.95 km) |
| Difficult Run to Bucksburn | 3,491.25 mi (5,618.63 km) |
| Difficult Run to Bude | 3,509.32 mi (5,647.71 km) |
| Difficult Run to Bulwell | 3,602.96 mi (5,798.40 km) |
| Difficult Run to Burbage | 3,606.47 mi (5,804.05 km) |
| Difficult Run to Burgess Hill | 3,689.94 mi (5,938.38 km) |
| Difficult Run to Burnham | 3,655.09 mi (5,882.31 km) |
| Difficult Run to Burnham-on-Sea | 3,565.56 mi (5,738.22 km) |
