I live about 40 minutes north of the downtown Convention Center, depending on the time of day and traffic. I think I've only been all the way downtown there about four times in the sixteen years I've lived here, so I'm no help with recommendations.

Unless you mean the Town and Country Convention Center in Mission Valley, which is a whole 'nother story. I drive by that every weekday and the Y I go to, which does have spin classes, but not the fancy environmental thing, is a couple blocks away. It does have a really nice lap pool with open swim all day -- two, actually, one indoor and one outdoor -- and a locker room and hot sauna. I like it. I think it opens at 5am or something, and I've worked out there myself as late as 9:30 or so.

Roxy