sweat can clog your pores causing break outs.

you can always try the stuff i use. its a PH balance body and face wash. you can buy it at any drug store its called phisoderm. its worked extreemly well for me and i had horrible acne sometimes
now i barely ever see a pimple. oh and since its ph balanced it will NOT dry or make your skin red

It depends.
My advise:
*Ask your roommate if you can shower first, at least every other time.
You should shower asap and avoid wearing makeup while working out.
*And you could wash your face while she showers at the kitchen sink, and just rinse with water during your actual shower (too much washing can cause irritation and dryness that also causes acne to worsen)
*Also wash your face with just water or a gentle cleanser before working out.
*****But whatever you do, do NOT stop working out!!! regualr exercise is VERY important to keeping your hormonal balance and therefore clear skin!

You can try Scented Neem oil because Neem oil extract is found effective on many types of diseases including skin disorders, peridontal disease, etc... Neem oil's highly concentrated anti-microbial active ingredients can be used directly on cuts, scrapes, or serious skin conditions.