Aged-based categories:
Age is determined by how old you are on December 31 of the current year. In Canada ‘master’ age categories increase in 10 year intervals: 35+, 45+, and so on (shorter intervals from 75+)
M= men; W or F = women.
Women may compete in men’s categories (OC rule 6.1.1).
Adults:
M35+ is for men 35 and older; so a 47 year old could compete in this category if they wished.
W55+ is for women 55 and older; so a woman who is, say, a very fit 68 might want to compete in this category.
W21+ is for women 21 and older.
M21+ is for men 21 and older.
Women may compete in men’s categories (OC rule 6.1.1).
Juniors:
M or W 10- is for juniors 10 and under (by the end of the current year)
M or W 12- is for juniors 12 and under (by the end of the current year)
M or W 13/14 is for juniors 13 or 14 (by the end of the current year)
M or W 15/16 is for juniors 15 or 16 (by the end of the current year)
M or W 17-20 is for juniors 17 to 20 (by the end of the current year)
Juniors may complete in one level higher than their age. Juniors under 16 must have formal permission from the Event Director or the Controller to run in more than one higher age category.(OC rule 6.1.3)