Is it good for skin condition to expel waste products through sweat?

Although people still mainly exercise indoors, once the weather gets a little warmer, many people go outside to run or work out, sweating more than usual.

I seem to get fewer pimples, perhaps because the impurities are being flushed out, but I am concerned about how dry my skin becomes right after exercising. It feels like the beneficial oils that protect my skin are being lost along with it. I'm confused whether this is good or bad for my skin.

Clinics and cafes always say that staying hydrated is the most important thing. I know that, but besides drinking plenty of water, what other good methods are there?