Race Categories
Category A
at least 250 ft (76.2 m) of ascent per mile (1.6 km)
should not have more than 20% of the race distance on road
should be at least one mile in length
Category B
at least 125 ft (38.1 m) of ascent per mile (1.6 km)
should not have more than 30% of the race distance on road
Category C
at least 100 ft (30.5 m) of ascent per mile (1.6 km)
should not have more than 40% of the race distance on road
should contain some genuine fell terrain
Category L
for Long - over 12 miles (19.3 km)
Category M
for Medium - over 6 miles (9.6 km)
Category S
for Short - less than 6 miles (9.6 km)