Effects of 12-week circuit exercise program on obesity index, appetite regulating hormones, and insulin resistance in middle-aged obese females.

Only 26 women were studied, all from one health promotion center in South Korea, so the results may not apply to other groups. The paper does not describe how randomisation was done, whether participants or assessors were blinded, or whether a primary outcome was pre-specified. All participants were instructed to record and voluntarily reduce food intake, and dietary habits were not completely controlled, so the effect of circuit exercise alone cannot be separated. Daily physical activity was not analyzed, so differences in usual activity between groups are unknown. Fasting glucose did not significantly decrease in the exercise group. No follow-up beyond 12 weeks is reported.

Do not conclude that circuit exercise alone caused the weight, hormone, and insulin changes. All participants also recorded food intake and were instructed to voluntarily reduce consumption, and the study did not fully control diet.