Effects of High-Intensity Resistance Training on Circulating Levels of Irisin in Healthy Adults: A Randomized Controlled Trial

Abstract

Background: Existing research suggests that irisin increases in response to exercise in humans. However, results are controversial and a majority of the studies lack a control group. The present study aimed to analyze the effects of both one-bout, and three-week intense resistance training on physical fitness (body composition and strength) and serum irisin levels when compared to a control group. Methods: A total of 26 healthy young adults (n = 14 males; 12 females) completed the pre-assessment phase, and were randomly assigned to either intervention or control group. Physical activity, diet, and physical fitness (strength, cardiorespiratory fitness, and body composition) were assessed. Blood samples were collected at baseline, during and post one-bout of exercise, and baseline on sessions 1, 3, 6 and 9 of 3-week high intensity resistance training (3 times per week). Results: None of the ANOVA effects on irisin concentration were significant after one-bout of exercise or 3 weeks of resistance training. The intervention group showed large significant changes from pre to post in relative body fat (%BF) (t (13) =-3.37, P = 0.003), and lean body mass (P = 0.016, d = 0.72). All muscle strength variables (1RM bench press (F (1,22) = 19.54, P < 0.001, η 2 G < 0.01); 1RM leg press (F (1,22) = 20.84, P < 0.001, η 2 G = 0.03); bench press-to-body weight ratio (F (1,22) = 18.93, P < 0.001, η 2 G = 0.01); leg press-to-body weight ratio (F (1,22) = 23.03, P < 0.001, η 2 G = 0.05)) showed significant group by time interaction effects. Conclusions: Serum irisin concentrations did not change during or post one-bout, nor during three-weeks of high-intensity resistance training compared to matched controls, while the program elicited significant changes in body composition and muscle strength in a group of healthy young adults. Only irisin levels in the control group were significantly increased. Additionally, no significant associations were found between irisin levels and physical activity, diet, or physical fitness. However, negative associations were found between baseline serum irisin concentrations and body composition (body weight and skeletal muscle mass) in males.

Effect of high-intensity circuit training on obesity indices, physical fitness, and browning factors in inactive female college students

“…In a study by Hecksteden et al (2013) , the group performing aerobic and resistance exercises for 26 weeks showed no significant changes in the irisin level as compared to the control group. In a study conducted on healthy adults of the same age group as in this study, the irisin levels did not show any significant changes after short-term or 3-week long high-intensity resistance training exercises ( Fernandez-del-Valle et al, 2018 ). A review of the irisin level after a short-term exercise reported that the level increased by approximately 15% on an average ( Fox et al, 2018 ), but a review of the irisin level after a long-term exercise reported no change after the exercise ( Qiu et al, 2015 ).…”

Long-Term Effect of Exercise on Irisin Blood Levels—Systematic Review and Meta-Analysis

“…Several kinds of physical exercise increased irisin blood levels among healthy people as well. High-intensity interval training increased irisin in young, healthy males [41,60] and healthy young adults [43], military aerobic training [48] increased irisin blood levels in young, healthy males and one study with a single group design found a significant increase in irisin in young females after treadmill exercise [37]. On the other hand, cycle ergometer-sprint training, consecutive training [77] as well as indoor running [64] led to a decrease of irisin blood levels in young, healthy males, and the same effect was found after basketball training in healthy children [39] or after taekwondo training in obese children [70].…”

“…The basic description of the included studies is presented in Table 2. [38] Iran RCT Obese with metabolic syndrome 54 F 53.5 (6.5) Dündar [39] Turkey RCT Healthy 34 M 14.5 (1.1) Dünnwald [40] Austria NRT; N-CG Type II diabetes 14 T 59.6 (5.7) * Eaton [41] Canada SGS Healthy 9 M 20.5 (1.5) Ellefsen [42] Germany SGS Healthy 18 F 26.0 (6.0) Fernandez-del-Valle [43] US RCT Healthy 26 T 21.2 (1.9) * Ghanbari-Niaki [44] Iran RCT Healthy 24 F 55.7 (4.9) Hecksteden [45] Germany RCT Healthy 102 T 49.0 (7.0) * Huang [46] China SGS Obese 22 T 22.1 (2.8)…”

Sedanter, sağlıklı, genç erkek bireylerde akut tüm vücut titreşim egzersizinin serum irisin seviyelerine etkileri

“…Öte yandan, kronik egzersize yanıt olarak irisin ve FNDC5 düzeylerinin azaldığı gösterilmiştir [2,13,20,21]. Egzersizin irisin ve FNDC5 seviyelerini etkilemediğini bildiren çalışmalar da vardır [7,13,22,23]. Veriler arasındaki uyumsuzluklar, deneklerin yaşı, cinsiyeti, sedanter veya sporcu olmaları, yapılan egzersizlerin akut veya kronik olması, uygulanan egzersizin tipi, şiddetti ve süresi arasındaki farklılıklardan kaynaklanıyor olabilir.…”