Irisin levels before and after physical activity among school‐age children with different <scp>BMI</scp>: A direct relation with leptin

Circulating irisin is positively linked to BMI and leptin in school-age children, supporting the notion that that irisin is produced by adipose tissue. As in previous reports, this study failed to observe changes in irisin levels after exercise, likely because higher irisin levels are produced only during exercise.