The impact of abbreviated progressive muscle relaxation on salivary cortisol and salivary immunoglobulin A
This study on immunoenhancement was an attempt both to extend and to replicate the findings of an earlier study by the author, which found that a brief session of Abbreviated Progressive Relaxation Training (APRT) lowered experimental subjects' pre- to post-intervention salivary cortisol levels, while a same-length control session of quiet sitting did not have the same effect on control subjects. While salivary cortisol is often labeled an immune system variable in the literature, it is in actuality a product of the endocrine system. This study aimed to extend the work of the previous experiment by adding a true immunological variable, salivary immunoglobulin A (sIgA). Forty-one experimental subjects were lead through APRT during a one-hour laboratory session; fourteen control subjects merely sat quietly in the laboratory for an equal amount of time. Results indicated that a brief relaxation exercise lead to experimental subjects having significantly lower levels of post-intervention salivary cortisol and significantly higher levels of post-intervention sIgA than control subjects.