I would not put a wood-look tile next to real hardwood. If you're adding any equiptment to the workout room, even combined with office/guest usage, I would stick with tile. Look for a stone look tile in a medium to dark color so it flows with your dark floors but isn't trying to match exactly.

I like cork floating flooring in a work out room. It is often 1/2" thick and can accept 3mm, 6mm and 12mm cork underlay to add a 'quick' lift to the floor height. Cork is excellent at noise deadening and is wonderful for work outs as it helps protect joints from damage.

Check these guys out...they have some lovely marble mimics that look very much like stained maple. This is one of my personal favourites:

WALNUT BURLWOOD 12mm Cork Floating Flooring Uniclic 17.44 sq.ft per box (icorkfloor.com)

It is extremely handsome when installed. It will be the same price as a medium grade vinyl ($4-$6/sf).

SJ McCarthy - Is this flooring durable enough for a rolling office chair or would I need to protect the floor with a chair mat?