Progressive relaxation is subject to many procedural variations. Although most investigators follow the 5-7 s tension interval advocated by Bernstein and Borkovec (1973), longer tension intervals may contribute to greater relaxation effects. This study compared tension intervals of 5, 15, and 45 s. Since the development of control over muscle tension requires attention to feedback signals, a focus on internal proprioceptive sensations was contrasted with an external condition in which the subjects silently subtracted numbers immediately following the tension-release cycle. Longer periods of tension resulted in lower EMG levels, with the 45-s tension interval producing the greatest relaxation. Those individuals who focused on physiological sensations during training were able to achieve greater levels of relaxation after the training phase was completed. There was a significant interaction between tension interval duration and focusing; subjects in the 45-s interval who focused on physiological functioning showed the greatest arousal reduction. Anxiety level did not differentially influence the effects of procedural variations in training. Clearly, additional parametric studies in relaxation training are needed.