Therefore, we set out to compare, in six women with obesity (BMI ≥30 kg/m2) and five healthy women (BMI 22–29.9 kg/m2), the effect of an acute bout of moderate-intensity, continuous cycling exercise (60 min, 60% VO2peak) on the release of myokines (IL-6, IL-8, IL-10, IL-13, IL-15, SPARC, and FGF21) in plasma for a 24-h time course. Here, FGF21 is linked to obesity due to melanocortin 4 receptor deficiency.