Progressive relaxation exercises and human gastric acid output—A study using telemetric measurements

The effect of progressive muscle relaxation exercises on human gastric acid output was examined using a modification of the Heidelburg Capsule pH telemetering equipment. Fourteen healthy subjects practiced the exercises eight times before the post-exercise acidity measures were compared with control periods in the same session. No mean difference in acidity was observed. It is suggested that gastric acid secretion is more related to cognitive rather than somatic activity. Eleven of the 14 subjects reported feeling physically relaxed yet 7 of these increased acidity. Gastric acid secretion is vagally mediated through the parasympathetic nervous system. Muscle relaxation is associated with lowered sympathetic arousal. It is possible that the relaxation exercises led to increased parasympathetic arousal concomitant with sympathetic lowering since the two systems frequently act antagonistically. Progressive relaxation training does not appear to be an effective method of decreasing gastric acid output.