Intruduction: Wnt1-inducible signaling pathway protein 1 (WISP1), a member of the CCN family of intercellular signaling proteins, is a new adipokine that links obesity to inflammation and insulin-resistance. Therefore, the purpose of this study was to compare the effects of interval and continuous training on levels of WISP1, tumor necrosis factor-α (TNF-α) and insulin resistance in obese/overweight girls.
Methods: This quasi-experimental study was a pretest-posttest design. Thirty-two overweight/obese girls aged 9-11 years-old, BMI 25.40±2.92 kg/m2 were randomly assigned to three groups of interval (n=12), continuous (n=11) and control (n=9). Continuous and interval training were performed for eight weeks and three days per week (30-min walk in the continuous and interval groups with 60-75%HRmax and 70-85%HRmax, respectively). Levels of WISP1, TNF-α, and insulin-resistance (HOMA2) were measured at 72 hours the pre-test and after the last training session. Data were analyzed using factorial repeated measures of analysis of variance using SPSS version 21 at p<0.05.
Results: After eight weeks, WISP1 levels increased significantly in the control-group (p= 0.001), however, the increase and decrease observed in the interval and continuous group respectively were not statistically significant (p=0.095, p=0.400 respectively). There were no significant changes in TNF-α levels in any of the groups (p> 0.05). In the control-group, the HOMA2 index significantly increased (p=0.016) and it decreases in the continuous training-group, which was significant in comparison to the control-group (p= 0.046). BMI, waist to height ratio and fat percentage were improved in both training groups (p<0.05).
Conclusion: Although both interval and continuous training improved the body composition of overweight/obese girls, only continuous training could reverse the increasing trend of WISP1 and HOMA2 levels. The continuous training can probably be considered as one of the effective strategies for improving insulin sensitivity in obese children.