We compared the electrical activity of certain powerhouse muscles—External Oblique, Multifidus, Adductor Longus, and Gluteus Medius—during the teaser exercise of the Pilates Method, performed on various types of apparatus—the Mat, Reformer, and Wall Unit. Fifteen female practitioners of the Classic Pilates Method (32.6 ± 7.7 years old; 21.9 ± 1.9 body mass index) performed the teaser in each situation while electromyographic (EMG) and kinematic data were collected. Root mean square values of the flexion phase were compared. All muscles showed higher EMG activity in Reformer compared with Wall Unit, and Multifidus, Adductor Longus, and Gluteus Medius showed higher EMG activity in Mat compared with Wall Unit. No difference was found between Reformer and Mat.