Hi Karen,
Thanks for helping us narrow down your options. I would NOT pick Loews based on your criteria (even though the rooms are pretty nice). It's a bit down what is called the Silver Strand. It's away from everything and you most likely need a car to get somewhere. Also, I would NOT recommend running or biking along this road as there really isn't a good bike lane here.
Anyone on this board have feedback of the hotels on Harbor Island? I'm thinking of this area because it's on the water, it's right on a set of several bike/jogging paths, and not far from where you want to go (zoo, Sea World, etc.). In fact, you can take your bike and ride down to the Embarcardero, catch the ferry, and go over to Coronado Island. The only downside of this location is it's across the street from the airport; however, this location is NOT on the flight path.
Anyone have feedback of the Hilton San Diego Resort on Mission Bay? It looks really nice from the outside and is a AAA rated 4 diamond resort hotel (and appears to be in your price range). Number is 619-276-4010. This hotel is right on some awesome bike/jogging paths (my roomie and I cycle past this from home). You can bike to Sea World as it's only a mile away. It is right on Mission Bay and offers canoe, bike, and paddleboat rentals. It does have both a spa and a gym. However, I'm not sure what equipment is in this gym. Anyone know???? Lastly, a cab ride shouldn't be too expensive to where you want to go (you could cycle to the Zoo if you want if you don't mind some steep hills). The only downsides of this place are: it's not near restaurants and it's right off the freeway.
I'll keep looking for other hotel options for you. Right now, I have to scoot and do my Cathe workout.
Lorrayne