Circulating Tumor Necrosis Factor Alpha May Modulate the Short-Term Detraining Induced Muscle Mass Loss Following Prolonged Resistance Training.

Autor: McMahon G; Sport and Exercise Sciences Research Institute, Ulster University, Belfast, United Kingdom.; Musculoskeletal Science and Sports Medicine Research Centre, Manchester Metropolitan University, Crewe, United Kingdom., Morse CI; Musculoskeletal Science and Sports Medicine Research Centre, Manchester Metropolitan University, Crewe, United Kingdom., Winwood K; Musculoskeletal Science and Sports Medicine Research Centre, Manchester Metropolitan University, Crewe, United Kingdom., Burden A; Musculoskeletal Science and Sports Medicine Research Centre, Manchester Metropolitan University, Crewe, United Kingdom., Onambélé GL; Musculoskeletal Science and Sports Medicine Research Centre, Manchester Metropolitan University, Crewe, United Kingdom.
Jazyk: angličtina
Zdroj: Frontiers in physiology [Front Physiol] 2019 May 03; Vol. 10, pp. 527. Date of Electronic Publication: 2019 May 03 (Print Publication: 2019).
DOI: 10.3389/fphys.2019.00527
Abstrakt: Introduction: Tumor necrosis factor alpha (TNFα) is a pro-inflammatory cytokine that has been shown to modulate muscle mass, and is responsive to exercise training. The effects of resistance training (RT) followed by a short period of detraining on muscle size, architecture and function in combination with circulating TNFα levels have not been previously investigated in a young, healthy population.
Methods: Sixteen participants (8 males and 8 females) were randomly assigned to a training group (TRA; age 20 ± 3 years, mass 76 ± 7 kg), whilst fourteen participants (7 males and 7 females) age 22 ± 2 years, mass 77 ± 6 kg were assigned to a control group (CON). Measures of vastus lateralis (VL) muscle size (normalized physiological cross-sectional area allometrically scaled to body mass; npCSA), architecture (fascicle length; L F , pennation angle Pθ), strength (knee extensor maximal voluntary contraction; KE MVC), specific force, subcutaneous fat (SF) and circulating TNFα were assessed at baseline (BL), post 8 weeks RT (PT), and at two (DT1) and four (DT2) weeks of detraining.
Results: Pooled BL TNFα was 0.87 ± 0.28 pg/mL with no differences between groups. BL TNFα tended to be correlated with npCSA ( p = 0.055) and KEMVC ( p = 0.085) but not specific force ( p = 0.671) or SF ( p = 0.995). There were significant ( p < 0.05) increases in npCSA compared to BL and CON in TRA at PT, DT1, and DT2, despite significant ( p < 0.05) decreases in npCSA compared to PT at DT1 and DT2. There were significant ( p < 0.05) increases in L F , Pθ and KE MVC at PT but only L F and torque at DT1. There were no significant ( p > 0.05) changes in SF, specific force or TNFα at any time points. There was a significant correlation ( p = 0.022, r = 0.57) between the relative changes in TNFα and npCSA at DT2 compared to PT.
Discussion: Neither RT nor a period of short term detraining altered the quality of muscle (i.e., specific force) despite changes in morphology and function. TNFα does not appear to have any impact on RT-induced gains in muscle size or function, however, TNFα may play a role in inflammatory-status mediated muscle mass loss during subsequent detraining in healthy adults.
Databáze: MEDLINE
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