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Background & objectives:�Mostly, strengthening the immune system is possible by consumption of body energy through physical activity that prevents persons from sicknesses due to sedentary life in the years following childhood. The aim of this study was to investigate the response of inflammatory, immune and hormonal markers to incremental exercise in the healthy girls.

Methods:�This�quasi- experimental study was performed in the spring of 2014. Twenty eight 10-12 years old healthy female children from Urmia province of Iran were selected by cluster sampling method. They were divided randomly into two groups experimental and control. Brachial vein blood samples were collected by the nurse in the two stages before and immediately after a session of Graded exercise test. ELISA method was used for measurement of immunoglobulin (I, G, M), cortisol, creatine- kinase, and C-reactive protein and fibrinogen serum levels. The data were analyzed using the Pearson’s correlation coefficient test, multiple linear regression, independent and paired t-test on SPSS (v. 21).

Results:�Immediately after exercise, IgA (p=0.012), IgG (p=0.028), IgM (p=0.027), creatine ki-nase (p=0.039), fibrinogen (p=0.011) and CRP concentrations (p=0.048) were decreased significantly but cortisol level (p=0.001) was increased in the experimental group. A positive relationship was observed between inflammatory (creatine-kinase, CRP and fibrinogen) and immune (immunoglobulin I، G and M) markers (p=0.05) after exercise. There was a negative relationship between immune (immunoglobulin I، G and M) and hormonal (cortisol) markers (p=0.05) and also between inflammatory (creatine-kinase, CRP and fibrinogen) and hormonal (cortisol) markers (p=0.05).

Conclusions:�With regard to changing in inflammatory and hormonal markers in response to intensive exercise, girls’ immune system is weakened. Also results of this study is so important in the pathology of Immune system, muscular damage and inflammation for cutting intensive exercise training programs and codifying suitable training programs such as moderate intensity exercise for children.