I'll be happy to answer both questions.
Health Clubs/Spas/Fitness Centers are available at:
Disney's Animal Kingdom Lodge, Zahanati Fitness Center
Disney's Boardwalk Resort, Muscles and Bustles Health Club
Disney's Contemporary Resort, Contemporary Health Club
Disney's Coronado Springs Resort, La Vida Fitness Center
Disney's Saratoga Springs Resort & Spa, The Spa at Disney's Saratoga Springs Resort
Disney's Grand Floridian Resort, Grand Floridian Resort and Spa
Disney's Old Key West Resort, Old Key West Resort Fitness Center
Disney's Yacht & Beach Club Resorts, Ship Shape Health Club
The Villas at Disney's Wilderness Lodge, Sturdy Branches Health Club
Hours:6:00am - 9:00pm
Age requirements: Guests age 14 to 17 allowed but must be accompanied with a parent or guardian.
Fitness Center Prices: $12 per day per Guest (age 14+) of any other Walt Disney World resort. Complimentary with Massage, Facial, or Body Treatment or for guest of the resort where the fitness center is located.
Swimming Pool hopping is not allowed. To prevent overcrowding, each resort's swimming pool is for the exclusive use of the guest staying at that Resort only. Do note, that some resorts are "sister" resorts, were all amenities are shared including the pools.
Hope this helps! :sohappy: