Acute Effect of Concurrent Exercise on Serum Leptin and Resistance Insulin Response in Sedentary Men

Aim: This study aimed to determine the delayed effect of one session of concurrent exercise on serum leptin and resistance insulin levels of sedentary men. Materials and Methods: Fifteen healthy young men with a mean age of 22.9 ± 1.7 years and a body mass index of 23.3 ± 1 kg/m2 voluntarily participated in this experimental research. They participated in one session of concurrent exercise including 20 min of aerobic running on a treadmill at 60%–70% maximum oxygen uptake plus a resistance exercise at the intensity of 70% of 1‑repetition maximum with ten repetitions per set to second round. Blood serum leptin, glucose, insulin, and insulin resistance index were assessed before, 24, 48, and 72 h after the exercise program. Results: The results showed that leptin level did not change statistically significantly immediately and 72 h after the exercise termination (P 0.05) but did decrease statistically significantly 24 and 48 h after the exercise program (P ≤ 0.05). The result also showed that insulin and insulin resistance levels decreased statistically significantly immediately after the exercise and lasted for up to 48 h postexercise (P ≤ 0.05); however, it returned to its initial value after 72 h of recovery (P 0.05). Conclusions: It was concluded that energy use in one session of concurrent exercise might reduce leptin levels up to 48 h of recovery. In addition, a decrease in insulin, a known inducer of leptin expression in adipocytes, occurs before the decrease in leptin. This change may mediate the decrease of leptin concentration.