Effects of exercise on the circulating concentrations of irisin in healthy adult individuals: A review

Aims. Irisin is a myokine induced by exercise and is responsible for regulating the uncoupling protein 1 (UCP-1) in beige fat. The aim of this review was to examine evidences that acute and chronic exercise influence the circulating concentrations of irisin in healthy adult individuals. News. A review of articles published between January 2012 and March 2016 was conducted in Medline and ScienceDirect databases using the following index terms: irisin, acute exercise, chronic exercise and exercise training. Original studies on the effects of exercise on the circulating concentrations of irisin in healthy humans are included. For analysis, the studies were divided into acute exercise and chronic exercise. Sixteen articles met the inclusion/exclusion criteria, eight studies on acute exercise, four on chronic exercise and four on both. Only two out of eight studies on acute exercise did not observe increases in serum and plasma concentrations of irisin after the exercise session. Resistance and high-intensity exercise were more effective in increasing the circulating concentrations of irisin as compared with aerobic and low-intensity exercise, respectively. Regarding chronic exercise, only one study found increased circulating concentrations of irisin when compared post- and pre-training data. Another study observed increased circulating concentrations of irisin in trained group as compared to control group. Conclusion. Acute exercise increases the circulating concentrations of irisin; and resistance and high-intensity exercise protocols were more effective. Chronic exercise seems not to affect the concentrations of circulating irisin. (C) 2016 Elsevier Masson SAS. All rights reserved.