This review is more focused on the Hart House gym and fitness classes. I really love Hart House. As a student, I used to go to the gym at Hart House because people were not as hardcore as they were at the Athletic Centre. Fast forward to 2015, I'm still going to Hart House for exercise.
I primarily take a ballet class there with a wonderful instructor named Portia Wade. She teaches all the ballet classes there. She is great and the ballet classes are great! I take various ballet classes around the city and this is the only one where my teacher actually offers corrections. She gives one on one advice to each student. She inspired me to go further with my new hobby and I am better for it.
I find that some of those relaxing parts of my day are spent in my ballet class or in the shower afterwards. There is always shower availability - even during peak times (read - January New Year's Resolution people). There are also always full length lockers available and the charge rooms are nice and warm in the winter so you don't freeze tottering back to get dressed.
Definite must-try if you live in the area, are faculty/staff or student/alumni.