The first link I am providing is great article that helps to explain the great mental side of hiking. We all know a good hike can be a fun, rewarding, enjoyable, and physically demanding accomplishment. But there is so much more that a hike can help us with!
http://www.collective-evolution.com/2016/04/08/doctors-explain-how-hiking-actually-changes-our-brains/
We live in the great Pacific Northwest where there are hiking trails all around us. Some we may never even know are there unless someone else tells us about them.
I am providing a link to 10 hikes within 30 minutes of Seattle. I personally love PooPoo point for a good elevation gain and nice Bellevue, Seattle, and Mt Rainier views. I also thoroughly enjoy Discovery Park: great views of the shipping lanes, Mt Rainier, nice beach, and old lighthouse at the beach. It's a bit of a descent, with built in steps.
If you need help getting "hike ready" your friendly Peak PT's are here to help!
Here is the link for the hikes from Washington Trails Association:
http://www.wta.org/go-hiking/seasonal-hikes/regional/hikes-30-minutes-from-seattle
