Walking calms the parasympathetic nervous system and provides gentle exercise without the need for a gym membership or bulky equipment.
In the valley, there are numerous close-in trails where one can feel enveloped in natural beauty. Terrains range from short 1/2 mile loops on boardwalks (Jackson-Frasier Wetlands) to McDonald Forest's more than 80 miles of trail through old growth and foothills. The Benton County public library has put a PDF of Phillip Hays' guide to Corvallis trails on-line-- find it here.
Resolve to spend a half hour or a day in the woods, and see what it brings you.