Choose Sister Bay Athletic Club. Sister Bay Athletic club is your premier boutique fitness club located in the beautiful Country Walk Shops in Door County's Sister Bay, WI,. You will find us between Twisted Tree at The Pharm and Church Hill Inn. Sister Bay Athletic Club (SBAC) combines the highest quality experience, service, instruction and amenities of a high- end fitness club with the warmth, connection and playfulness of a small boutique studio. We strive to provide our members with education, instruction and encouragement to inspire and support thier most vibrant and exceptional lifestyle. Offering cardio, strength training, personal training, yoga and more! Come check us out!