Will's(威尔士健身会所)

One of the best gymnasiums in Shanghai. The equipments are good. The coaches are more professional than other gymnasiums. It is expensive here. A card for unlimited entries in a year is not too much though, usually costs 2000 to a little more than 3000 RMB depending on how much the discount is. Most of their branches are in urban areas, so it is convenient to find one near your offcic and sweat a little bit after a day's work.
All About Shanghai www.allaboutsh.com
Look for their branches here:
http://www.willsgym.com/clubs_en.php