Psychology Ph.D. Dissertations

Worry, Respiratory Sinus Arrhythmia, and Health Behaviors

Date of Award


Document Type


Degree Name

Doctor of Philosophy (Ph.D.)



First Advisor

William O'Brien

Second Advisor

Robert Carels (Committee Member)

Third Advisor

Casey Cromwell (Committee Member)

Fourth Advisor

William Morrison (Committee Member)


Research has generally shown that worry leads to a decrease in respiratory sinus arrhythmia (RSA) and cardiac vagal activity. Low vagal activity has been associated with a variety of physical ailments, including cardiovascular disease. However, research has also revealed inconsistencies in the relationship between worry and RSA, and the assessment of possible moderating relationships is lacking. The present study investigated the relationships among trait and induced worry on RSA, as well as a number of health behavior moderators, in a sample of undergraduate students. One hundred-fifteen participants completed a pretest measure of worry along with a number of protective health behavior measures. While having their heart rate measured (RSA), participants engaged in a 10-minute baseline condition, a 5-minute worry condition, a 5-minute control condition, and a 10-minute recovery condition. Consistent with predictions, high trait worriers who reported higher levels of physical activity displayed significantly higher levels of RSA, relative to high trait worriers who also reported lower levels of physical activity. Moreover, the same effect was not found for low trait worriers. Possible cardiovascular health implications, as well as implications for effects of physical activity on worry from an afferent perspective, are discussed.