A Comparison of the Effect of Morning and Evening Exercises on Salivary Immunoglobulin A, Cortisol, and Total Proteins in Middle-Aged Men

This study was designed to compare morning and evening exercises on a change in levels of salivary immunoglobulin A (IgA), cortisol, and total protein in middle-aged men. For this purpose, 12 middle-aged men (age: 53.42±6.87 years; BMI: 25.21±2.88 kg/m2) participated in this study. They had an endurance training session for 45 minutes with 65% of maximum heart rate in the morning (7 - 8 am) and evening (5 - 6 pm) with a 2-day interval. Salivary immunoglobulin A, cortisol, and total protein levels were measured in the morning and evening (before and after the exercise) by ELISA method. Data were analyzed using analysis of variance with repeated measures and Bonferroni post hoc test. The results showed that morning exercise significantly decreased salivary cortisol concentration levels (P=0.03). No significant changes were observed in other measures. In conclusion, morning exercises reduces salivary cortisol levels in middle-aged men.