I'll wear mascara to work then it'll still be on when I run after work but that's about it.
If women want to wear a full face of make up to run in, let them be. Does it really harm anyone? If it gives them a bit of confidence to go outside and run, does that make them a bad person? If young, self conscious women who see Jessica Ennis with a bit of eyeliner on when she's winning the heptathlon can think, "hey, maybe I can exercise too and still look a bit feminine, I might try that" - is that really to be criticised?
It's a bit manky wearing slap in a public swimming pool but unless people at races or in the gym are then rubbing their glowing faces across yours, why is it a problem?