Association of Exercise-Induced Salivary Cortisol to Exertional Perception and Affect

The purpose of this research study was to examine the association of cortisol levels to exertional perception and exercise induced changes in affect during a bout of exercise. It was expected that increased levels of salivary cortisol would be associated with a negative shift in affect in response to a submaximal and maximal treadmill test. It was also hypothesized that increased levels of salivary cortisol levels would be associated with an increased perception of exertion during a submaximal and maximal treadmill test. Males and females between 27 and 35 years of age (n=33) were recruited to participate in this study. Salivary cortisol was assessed at baseline, 5 minutes after the submaximal treadmill test, 5 minutes after the maximal treadmill test, and 30 minutes after the maximal treadmill test. Affect was measured using the Total Mood Disturbance (TMD) score of the Profile of Mood Scale (POMS). The greater the TMD scores, the more negative the mood. Affect was measured at baseline, 5 minutes after the submaximal treadmill test, 5 minutes after the maximal treadmill test, and 30 minutes after the maximal treadmill test. Perceived exertion (RPE) was measured using the OMNI Scale of Perceived Exertion. Final RPE for legs, chest and breathing, and overall body was assessed during the final minute of the submaximal treadmill test, and immediately at the end of the maximal treadmill test. Session RPE was assessed 5 minutes after the cessation of both the submaximal and maximal treadmill test. Partial correlations were conducted to examine the association between cortisol values, affect, and RPE. Results indicated there was a positive correlation between cortisol values and negative affect. This association was found only in males and the correlation was strongest in both the change in cortisol levels from baseline to 5 minutes and 30 minutes after the maximal treadmill test and the change in affect from baseline to 5 minutes after the maximal treadmill test. Final RPE assessed for the maximal treadmill test was positively correlated with cortisol levels 30 minutes after maximal treadmill test. This correlation was found only in females. There appears to be evidence that increased cortisol levels post exercise are associated with a negative mood shift following a maximal treadmill test and higher perceived exertion during a maximal treadmill test. Future examination of the association among cortisol levels, affect, and perceived exertion during exercise is warranted. Examining the physiological and psychological responses to exercise may assist with the development of better strategies that will help increase exercise adaptation and adherence