The Effect of 6-Week Resistance Training on Irisin, Parathormone and Alkaline Phosphatase in Overweight Postmenopausal Women: a Randomized Clinical Trial

Irisin is one of the myokines produced by skeletal muscle in response to exercise. Recent studies suggested that circulating irisin may play a vital role in bone metabolism. The present study aimed to investigate the effect of six weeks of resistance training on serum irisin, parathormone, and alkaline phosphatase levels in overweight postmenopausal women.

The 24 overweight postmenopausal women (51.87±2.30 years, 28.59±0.80 kg/m2) were selected and randomly divided into control and experimental groups equally. The experimental group performed a resistance training program for six weeks (3 sessions per week and one hour for each session). Exercises performed with an average intensity of 60 to 75% of a maximum repetition with a professional trainer. Also, fasting blood sampling was performed 24 hours before and 48 hours after the last training to assess irisin, parathormone, and alkaline phosphatase.

The results showed that six weeks of resistance training significantly increased irisin (P=0.04) and parathormone (P=0.05) in postmenopausal women but had no significant effect on alkaline phosphatase.

The results suggest that resistance training can be used as an appropriate exercise to increase the amount of irisin and some bone metabolism factors in postmenopausal overweight women. According to the evaluated irisin and parathormone values, Irisin might be the "connector" between bone health and physical activity.