As the holiday season approaches, many gyms and fitness centers offer special classes and activities to help keep people active during the festive period. Here are some of the best gyms that are open on Christmas Eve and Christmas Day: 1. Crunch Fitness - Crunch Fitness operates 24 hours a day, seven days a week, so you can always find a time to work out, even on Christmas Day. 2. Planet Fitness - Many Planet Fitness locations will be open on Christmas Eve and Christmas Day, but with limited hours.