Terminal 1, Before-Security (International), Level 1 Arrivals.
Arrivals Area Level F (Google Maps)
If you are between flights or need to liven up before or after your meeting in Toronto, head to Terminal 1 arrivals level and find Goodlife Fitness. If you don't have workout clothes you can rent everything including shoes and they store your luggage . If you aren't a Goodlife member, no problem, there is a very affordable fee and gives you access to cardio and weight training areas, showers and change rooms, towel service, and, of course, toiletries.