Not only will you get fresh air in your brain and lungs, you will also get a taste of something that presents itself exactly the way it was meant to be...I would say nature is the most honest thing on Earth, that it doesn't try to hide itself--what you see is what you get.
I have always found this notion to be comforting, and so running for the first time in months yesterday brought me back to that state of silence that you can enjoy for yourself.
So instead of sleeping in (which is nice too I'm sure ;) ), take some time to yourself to walk in the nature, and breathe in an air you can't find anywhere else.
P.S. I took these pictures during a jog in the park near my house last winter...It was a lovely, crisp, fresh winter morning and I didn't want to leave!...And I couldn't resist taking these pictures while running (well, not while running; I just kept stopping in my tracks to take them; though I didn't end up getting as big of a workout as I would have without my camera phone, I enjoyed being in the nature anyways :) ).