The effects of exercise on perceived stress and IL-6 levels among older adults.

Biochemical markers of inflammation have been used in recent physical activity intervention studies. However, these same biochemical markers, mainly proinflammatory cytokines, may also be influenced by the individual's level of stress and mood. Accordingly, this pilot study was implemented to determine the effect of a physical activity intervention on perceived stress, mood, quality of life, serum interleukin-6 (IL-6), and cortisol among 10 older adults, age 60 to 90. The results were compared to those of 10 older adults who were not engaging in regular physical activity. The 10-week intervention was applied using student nurses who taught the older adults how to calculate 60% of their maximum heart rate while ambulating for 30-min intervals. After the 10-week period, the participants in the exercise group reported significant improvements in stress, mood, and several quality of life indices. They also demonstrated a significant decrease in serum IL-6. Stress, mood, and quality of life scores in the exercise group were also significantly improved compared to the control group. This study adds information on the specific intensity, duration, and frequency of exercise necessary to achieve improvements in psychological variables and IL-6 levels. It also supports the need to measure psychological stress in physical activity intervention studies. Although the psychological variables were highly correlated, there were only weak correlations found with IL-6, suggesting that other factors are likely involved in reducing IL-6 when engaging in low-impact physical activity.