O.N. Athletics is a 24/7 gym serving Groton and Mystic, Connecticut, offering open gym access, strength training, CrossFit, personal training, and recovery amenities. Our 7,200+ square foot facility provides a clean, fully equipped training environment for beginners, experienced lifters, and athletes. Members have 24/7 access to strength and conditioning equipment, Olympic lifting platforms, free weights, machines, open training space, and a sauna. CrossFit Dyr provides group fitness classes and coaching for members looking for structured training and a supportive community.