Comparison of the effect of period of resistance, aerobic and concurrent training on irisin, CRP serum levels in obese women

The irisin hormone is a type of myocynia that is secreted immediately after physical activity in the skeletal muscle and flows in blood circulation. The aim of the current study was to compare the effect of a period of resistive, aerobic, and combined exercises on serum irisin, C-reactive protein (CRP) and insulin resistance of obese women.
In this semi experimental study, 36 obese women with the average (age: 33.27±6.82 years, weight: 76.11±9.73 kg, height: 156.18±5.21 cm and fat percentage 38.61±3.48) were selected by purposive and convenience sampling, and were divided into three groups of resistive (n=12), aerobic (n=12) and concurrent (n=12) exercises. First, weight, height, BMI, WHR, Vo2max and fat percentage were measured, and the blood sample was taken from participants. Then, resistance, aerobic and concurrent exercise programs were performed for 8 weeks. Resistance program with weight, 75% of one maximum repetition, aerobic exercise program, 75% of maximum heart rate and concurrent exercise program, a combined of aerobic and resistance groups, were implemented. 24 hours before and after eight weeks of exercise, blood sample of irisin, CRP, anthropometric indices were measured. To study the changes from pre-test to post-test, correlated t-test in each groups and for inter-group comparison, the one-way variance analysis test were used. In the case of observing significant results, the Bonferroni post hoc test was used. The significance level was considered as P≤0.05.
The results showed that performing eight weeks of aerobic and concurrent exercise programs caused increasing serum irisin and reducing CRP in all three groups. Increasing irisin in resistance group was not significant (P≥0.05). Also, no significant difference was observed for irisin and CRP among the three groups (P≥0.05).
Overall, findings showed that physical activity includes arobic exersise with
55-75% maximum heart rate and intensity 55-75% of 1RM is probAbly a stimulator for irisin secretion. Sport activity caused reducing CRP through secretion of myokines such as irisin. This result is an indicator for the role of anti-inflammatory of irisin.