The business runs gymnasiums and saunas. They are one of the sponsors of the North Point Trim Track in Paleto Bay. The gym in Rockford Hills is smaller but luxurious, judging by the location and its modern-looking frontage. The Downtown branch appears to be older and it is currently for rent. Some posters of Anna Rex can be found on the side of the buiding as well. Jack Howitzer wears a Muscle Gymnasium tank top during his TV show. Alongside this, Evan Moss wears a Muscle Gymnasium shirt in his appearance during The Ballad of Gay Tony.