Introduction: Secreted frizzled-related protein 5 (SFRP5), like adiponectin, is considered as a novel adipokine with insulin-sensitizing and anti-inflammatory characteristics. The purpose of this study was to investigate the effect of eight weeks of resistance training on serum SFRP5 concentration in obese men.

Methods: Twenty four obese men (age; 36.9 ± 8.5 yr, weight; 94.8 ± 10.7 kg, and BMI; 31.7 ± 2.4) voluntarily participated in this study and were divided into control and resistance training groups (n=12). Subjects in training group performed eight weeks resistance training in a circuit manner with 50-85% 1RM (3 days/week). Anthropometrics parameters and fasting serum glucose, insulin, and SFRP5 concentrations, as well as insulin resistance index (HOMA-IR) were measured at the baseline and at the end of study.

Results: Resistance training induced significant reductions in body weight, BMI, body fat percentage, waist and hip circumferences (P< 0.05). Also, significant reductions in serum insulin concentration and HOMA-IR scores were found when compared with control group (P<0.05). Eight weeks of resistance training did not significantly change in serum SFRP5 concentration in training group. Nevertheless, a significant decrease was found in the control group (P<0.05). The result of analysis of covariance (ANCOVA) showed a significant difference between the two groups in changes in serum SFRP5 concentrations (P<0.05).

Conclusion: It seems that resistance training could improve metabolic conditions at least by preventing a decrease in serum SFRP5 levels.