I agree that posting on gym boards would be useful. I have usually found that tear-off tabs about the size of a business card with all your contact information including a web site work well(some type A's need to be visually convinced).
You can download several flyer templates with space for tear-offs at Microsoft Office at http://office.microsoft.com/en-us/templates/results.aspx?qu=tear-off+tabs&av=TPL000. I am presumming that you are using the Evil Empire's (TM) software, smile.
If I were to use print ads, I would use the Puget Sound Business Journal, Seattle Business, and Daily Journal of Commerce in that order and maybe Seattle Magazine, Seattle Metropolitan, and Colors Northwest. You want to ask yourself, what are the high energy achievers reading (if they do)?
I strongly recommend Craig's List at http://seattle.craigslist.org. I have gotten 95% of my business through it (the other 5% is from BizNik) but be upfront with your rates and expectations like being paid at the time of service.
Some good categories you might want to look at would be events, financial, household, small biz, and therapeautic to name a few in the services category as well as putting up a resume as some high energy business folks look there for help or might discover you while looking for a personal assistant.
You might also want to think about approaching organizations like Rotary, Lions, or your local Chamber of Commerce to be a speaker (as a former Rotary member, I remember that it was always a problem to find interesting speakers.) Most local (weekly) newspapers list their meetings.
Microsoft (and many other companies) have an internal e-mail newsletter. Perhaps you could ask a friend who works there to post something for you. I am not sure that flyers would work in that environment. It seems very email oriented. Or find out who edits the newsletter and offer to write something for them and repost it on your blog. Their Alumni Network http://www.msanet.org/ might also be a source of referrals as well.