Leucine metabolites do not attenuate training-induced inflammation in young resistance trained men
Authors: Maria J Valamatos
Stuart M Phillips
Catarina N Matias
Luís B Sardinha
Francisco Alves
Robert W Morton
Filipe J Teixeira
Joana F Reis
Cristina P Monteiro
Journal: Journal of Sports Sciences (2019)
Discipline: CLINICAL MEDICINE
Keywords: Inflammation; hypertrophy; leucine metabolites; strength.
Affiliations: a Laboratory of Physiology and Biochemistry of Exercise, Faculty of Human Kinetics , Universidade de Lisboa , Cruz Quebrada , Portugal., b Laboratory of Exercise and Health, Faculty of Human Kinetics , Universidade de Lisboa , Cruz Quebrada , Portugal., c Center for the Study of Human Performance, Faculty of Human Kinetics , Universidade de Lisboa , Cruz Quebrada , Portugal., d Neuromuscular research Lab, Faculty of Human Kinetics , Universidade de Lisboa , Cruz Quebrada , Portugal., e Universidade Europeia , Lisboa , Portugal., f Department of Kinesiology , McMaster University , Hamilton , ON , Canada.

Abstract:  Leucine metabolites may reduce training-induced inflammation; however, there is scant evidence for this assertion. We conducted a double-blind randomized controlled pragmatic trial where 40 male participants were allocated into 4 groups: α-hydroxyisocaproic acid group ([α-HICA], n = 10, Fat-free mass [FFM] = 62.0 ± 7.1 kg), β-hydroxy-β-methylbutyrate free acid group ([HMB-FA], n = 11, FFM = 62.7 ± 10.5 kg), calcium β-hydroxy-β-methylbutyrate group ([HMB-Ca], n = 9, FFM = 65.6 ± 10.1 kg) or placebo group ([PLA]; n = 10, FFM = 64.2 ± 5.7 kg). An 8-week whole-body resistance training routine (3 training sessions per week) was employed to induce gains in skeletal-muscle thickness. Skeletal muscle thickness (MT), one repetition maximum (1RM), interleukin-6 (IL-6), high-sensitivity C-reactive protein (hsCRP) and tumour necrosis factor alpha (TNF-α) were assessed at baseline and at the end of weeks 4 and 8. Time-dependent increases were detected from baseline to week 8 for MT (vastus lateralis: p = 0.009; rectus femoris: p = 0.018), 1RM (back squat: α-HICA, 18.5% ± 18.9%; HMB-FA, 23.2% ± 16%; HMB-Ca, 10.5% ± 13.8%; PLA, 19.7% ± 9% and bench press: α-HICA, 13.8% ± 19.1%; HMB-FA, 15.5% ± 9.3%; HMB-Ca, 10% ± 10.4%; PLA, 14.4 ± 11.3%, both p &lt; 0.001), IL-6, hsCRP (both p &lt; 0.001) and TNF-α (p = 0.045). No differences were found between groups at any time point. No leucine metabolite attenuated inflammation during training. Additionally, backwards elimination regressions showed that no circulating inflammatory marker consistently shared variance with the change in any outcome. Using leucine metabolites to modulate inflammation cannot be recommended from the results obtained herein. Furthermore, increases in inflammatory markers, from training, do not correlate with any outcome variable and are likely the result of training adaptations. 

Retracted: No

PubPeer comments:
 Copy pasted from https: www.tandfonline.com doi full 10.1080 02640414.2020.1841407 :  Correction Page 2750 | Published online: 28 Nov 2020 Competing Interests Statement Dr. Phillips has a patent 3052324 issued to Exerkine, and a patent 16 182891 pending to Exerkine. Dr. Phillips reports personal fees from Enhanced Recovery (all proceeds are donated to charity), equity in Exerkine (all proceeds will be donated to charity), outside the submitted work. See https: retractionwatch.com 2021 02 12 eleven-papers-corrected-after-nutrition-prof-fails-to-disclose-patent-company-ties for backgrounds. ,