Skip Navigation LinksHome > Published Ahead-of-Print > Irisin Does Not Mediate Resistance Training-Induced Alterati...
Medicine & Science in Sports & Exercise:
doi: 10.1249/MSS.0000000000000286
Original Investigation: PDF Only

Irisin Does Not Mediate Resistance Training-Induced Alterations in RMR.

Scharhag-Rosenberger, Friederike; Morsch, Arne; Wegmann, Melissa; Ruppenthal, Sandra; Kaestner, Lars; Meyer, Tim; Hecksteden, Anne

Published Ahead-of-Print
Collapse Box

Abstract

Purpose: To investigate the effects of a 6 months preventive resistance training program on resting metabolic rate (RMR) and its associations with fat free mass (FFM) and the newly described myokine irisin as two potential mechanistic links between exercise training and RMR.

Methods: In a randomized controlled trial, 74 sedentary healthy male and female participants either completed six months of high repetition resistance training on 3 d [BULLET OPERATOR] wk-1 in accordance with the ACSM recommendations (RT: N = 37, 47 +/- 7 yrs, BMI 25.0 +/- 3.4 kg [BULLET OPERATOR] m-2) or served as controls (CO: N = 37, 50 +/- 7 yrs, BMI 24.2 +/- 3.2 kg [BULLET OPERATOR] m-2). Strength (1-RM), RMR (indirect calorimetry), body fat (caliper method), and serum irisin concentration (ELISA) were measured before and after six months of training.

Results: Training led to an increase in strength (1-RM leg press + 16 +/- 7%, P < 0.001). RMR increased in RT (1671 +/- 356 vs. 1843 +/- 385 kcal [BULLET OPERATOR] d-1, P < 0.001) but not in CO (1587 +/- 285 vs. 1602 +/- 294 kcal [BULLET OPERATOR] d-1, P = 0.97, group*time interaction: P < 0.01). Body weight (RT: -0.5 +/- 2.4 kg, CO: + 0.1 +/- 2.3 kg), body fat percentage (RT: -1.1 +/- 2.5%, CO: -0.7 +/- 2.9%) and FFM (RT: + 0.4 +/- 2.1 kg, CO: + 0.6 +/- 1.9 kg) did not develop differently between groups (group*time interaction: P = 0.29, P = 0.54, and P = 0.59, respectively). Serum irisin concentration increased in CO (+ 70.8 +/- 83.4 ng [BULLET OPERATOR] ml-1, P < 0.001) but not in RT (+ 22.4 +/- 92.6 ng [BULLET OPERATOR] ml-1, P = 0.67, group*time interaction: P < 0.01). The change in RMR was not associated with the change in FFM (r =- 0.11, P = 0.36) or irisin (r =-0.004, P = 0.97).

Conclusion: Preventive resistance training elicits an increase in RMR. However, in contrast to currently discussed hypotheses, this increase does not seem to be mediated by training-induced changes in FFM or circulating irisin concentration, which casts doubt in the meaning of irisin for human energy balance.

(C) 2014 American College of Sports Medicine

Login

Article Tools

Share

Search for Similar Articles
You may search for similar articles that contain these same keywords or you may modify the keyword list to augment your search.

Connect With Us