If you want a state-of-the-art gym experience, go to Extreme Fitness' brand new Yonge and Dundas location, which offers a large number of new cardio machines, a hot yoga studio, and wet, dry and cold saunas.
At Bloor and Yonge location, in the process of renovation, is its polar opposite. In its current condition, nothing could persuade me to actually take a shower there. For the time being, however, it is a serviceable - and very busy - gym.
Most recommended: Hatha yoga classes offered by Helen (Mondays) and Nancy (Wednesdays). Consummate professionals both, imagine how great the experience will be once you can have sauna after class.