Reductions In Total Resting Cortisol At Wake Following Moderate Intensity Resistance and Aerobic Exercise Training

Abstract

High levels of circulating cortisol (CORT) have been shown to have detrimental health effects in the general population, as well as increased mood and sleep disturbances. An increased level of CORT during the peak immediately before wake is also a known indication of increased stress. Individuals infected with HIV often exhibit elevated CORT levels due to a combination of the virus itself, anti-retroviral treatment, and daily social/environmental stressors. PURPOSE: To determine the effects of exercise training on morning CORT in HIV- infected men. METHODS: Forty HIV+ men were recruited for this study and randomized into either the exercise (EX) group or control (CON) group. The EX subjects participated in moderate intensity resistance training at 60% of their 3-rep max, as well as aerobic exercise on a treadmill or bike for 30 minutes at 60% of their age predicted heart rate max for a total of 6 weeks (twice per week). Salivary CORT at wake, +1 hour, and +2 hours was collected. The CON group received standard care during the same 6 week session and did not increase their activity level. RESULTS: The EX group showed a significant decrease in resting CORT at wake (p = 0.04) and +2 hours (p = 0.04) following the 6 week intervention. The area under the curve (AUC) was calculated by applying Simpson's 1/3 rule using the three time points in which saliva was collected (Wake, +1 hr, +2 hr). The EX group showed a significant decrease in AUC (p = 0.04) compared to the CON group which showed no change. CONCLUSION: These data show that HIV infected individuals have lower early morning CORT after engaging in moderate intensity resistance and aerobic exercise. Further, the total amount of circulating CORT over a time frame of two hours following wake declined overall in the EX group suggesting possible benefits with a successful long term moderate exercise intervention. This is supported by the NIH/NCMHD, the American College of Sports Medicine, and the Arnold School of Public Health.