Every parkrun event has a list of its top 500 fastest runners; however, our local event is gradually just becoming a list of men! There are only 25 women on the list, and the number is constantly decreasing. I made it on there for one week, (about 50 women at that point) before a man kicked me off. I'd now need to run over a minute faster than my PB in less than 21m30 to get back on the list.
YABU - all is fair, it's fastest 500 runners.
YANBU - this is not acknowledging women's achievements or physiological differences.