Abstract
The recently novel identified myokine, irisin, has gained attention as a way to increase energy expenditure by enhancing metabolic function. Exercise and active lifestyle increase the synthesis of contraction-regulated myokines that have direct effect on cells metabolism. PURPOSE: The objective of this study is to analyze the effects of one bout of high intensity exercise on circulatory levels of irisin in healthy young adults. METHODS: A total of 24 participants (age 21.3 ± 2.1 years, body mass index [BMI] 22.12 ± 1 kg/m2, lean body mass [LBM] 46 ± 10.1 kg, and relative body fat [%BF] 25.9 ± 9.9) were recruited. Subjects were blocked by sex, BMI, LBM, and %BF content and randomized to either control (n=13) or intervention (n=11). Physical Fitness was assessed by means of dual-energy x-ray absorptiometry (DXA), strength tests (Bench press and Leg press one repetition maximum [1RM]), and cardiopulmonary maximal stress test. Blood samples were collected to assess irisin at baseline, during (45 minutes), and post-intervention. RESULTS: Irisin (ul/ml) levels for control and intervention groups were 6.1 ± 1.7 and 5.77 ± 0.9 at baseline, 5.6 ± 1.3 and 6.03 ± 1 at 45-min, and 6.3 ± 1.9 and 5.8 ± 1.1 at post respectively. Interaction effect (time x intervention) was close to statistical significance (F[2,44]=3.106, p=0.055), and time (F[2,44]=0.837, p=0.440) and intervention (F[1,22]=0.091, p=0.766) factors were not significant. CONCLUSIONS: In addition to heterogeneous research findings, the lack of changes on serum concentrations of irisin after intervention shown in this study adds controversial results to the literature. Furthermore, values obtained on irisin concentrations in the control group resulted in more questions rather than answers. We hypothesize that, if irisin is an exercise-induced hormone, other confounding variables such as room temperature, or body temperature might be critical factors to control for future studies.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
