I have three clubs...
First one which is a social jogging group, almost entirely male, veyr few females. BUt group itself is only small about 20 total probably, with about ten turning up each week.
Second club is a larger running club though still not huge maybe 100+ members, probably about a 50/50 split, mixture of seniors and vets, though I'm normally by some way the youngest.
Third club is a proper athletics club, female dominated club, but a fair number of us lads as well. Age range is very young there, apart from coaches, most the girls are 16-19 or so, with the "younger" lads probably 10-15 and the older lads 18-25, nice atmosphere there, and a lot of fun on nights out!