I think it's usually a good idea to leave your skin alone as much as possible, because there really is a lot going on at the micro level. I'm not against makeup, but wearing it constantly might prevent your skin from renewing properly (the epidermis is constantly renewing itself) and may disrupt the acid mantle on it's surface.

I used to notice that I'd get this "glow" after working out or going for a run and my skin improved in minor ways (back when I still had consistent breakouts), so as vain as it sounds I became more active because I liked the improvement in my skin. But combined with the other physical and psychological benefits of exercise, it's become integrated into my life.

As far as noticing improvements like you said, this is probably due to the fact thatexercise temporarily increases inflammation during and immediatelyafter a workout, so the body responds to this byincreasing it's antioxidant production. So while it sounds counter-intuitive to increase inflammation, several studies haveconfirmed that people who exercise regularly have lowerinflammation levelsthan those who dont exercise. (a couple studies on thathere and here)

By all means, I think it's a great idea to exercise 🙂

Exercise like walking improves everything to do with health which means it helps your skinskin. And yes, chemical & emulsifierfilled occulsive liquid or cream makeup and other topicals are detrimental to skin function, so does soap.

See http://www.acne.org/messageboard/topic/330732-help-your-skin-function-stop-impairing-it/

No. I was told that a lot as well. And when I had acne, I have noticed that my skin was better when I wore my makeup vs no makeup.