The effect of high- intensity interval swimming training on irisin and metabolic syndrome in postmenopausal overweight women

Transmembrane protein fibronectin type III domain-containing protein 5 (FNDC5) is as a myokine, metabolic regulator and potential therapeutic agent which is known as a potential trait for metabolism and obesity. The purpose of this study was to evaluate the effect of high intensity interval swimming training on circulating irisin and some metabolic syndrome in postmenopausal overweight women. Thirty postmenopausal overweight women (55.73 ± 2.66 years, 26.72±2.33 kg/m2) were randomized into high intensity interval swimming training (n=15; HIIT) and control groups (n=15; CON). HIIT performed 6–10×30 s swimming interspersed by 2 min recovery for an 8-week period completing 24±1 session (average heart rate= 0.89±0.029% HRmax). Fasting blood samples were taken and body mass index was measured pre- and post-intervention. In CON, there was not significant change in all measured variables before and after the intervention period. Irisin increased (P<0.01) by 0.64±0.27 mg/ml in HIIT group. Insulin decreased (P<0.01) by 0.96±0.36 mg/dl while the blood lipid profile P= 0.78 cholesterol, P=0.14 TG, P=0.10 HDL, P=0.52 LDL, systolic blood pressure (P= 0.51), dyastolic blood pressure (P= 0.75), and BMI (P= 0.87) were unaltered. The result of present study showed that high intensity interval swimming trainings is an effectual and time-efficient training way for increasing irisin, and it can lead to compensatory irisin increases in postmenopausal overweight women.