Hammond, KM and Impey, SG and Currell, K and Mitchell, N and Shepherd, SO and Jeromson, S and Hawley, JA and Close, GL and Hamilton, DL and Sharples, AP and Morton, JP (2016) Postexercise High-Fat Feeding Supresses p70S6K1 Activity in Human Skeletal Muscle. Medicine and Science in Sports and Exercise. ISSN 1530-0315
Post exercise high-fat feeding supresses p70S6K1 activity in human skeletal muscle.pdf - Accepted Version
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PURPOSE: To examine the effects of reduced CHO but high post-exercise fat availability on cell signalling and expression of genes with putative roles in regulation of mitochondrial biogenesis, lipid metabolism and muscle protein synthesis (MPS). METHODS: Ten males completed a twice per day exercise model (3.5 h between sessions) comprising morning high-intensity interval (HIT) (8 x 5-min at 85% VO2peak) and afternoon steady-state (SS) running (60 min at 70% VO2peak). In a repeated measures design, runners exercised under different isoenergetic dietary conditions consisting of high CHO (HCHO: 10 CHO, 2.5 Protein and 0.8 Fat g.kg per whole trial period) or reduced CHO but high fat availability in the post-exercise recovery periods (HFAT: 2.5 CHO, 2.5 Protein and 3.5 Fat g.kg per whole trial period). RESULTS: Muscle glycogen was lower (P<0.05) at 3 (251 vs 301 mmol.kgdw) and 15 h (182 vs 312 mmol.kgdw) post-SS exercise in HFAT compared to HCHO. AMPK-α2 activity was not increased post-SS in either condition (P=0.41) though comparable increases (all P<0.05) in PGC-1α, p53, CS, Tfam, PPAR and ERRα mRNA were observed in HCHO and HFAT. In contrast, PDK4 (P=0.003), CD36 (P=0.05) and CPT1 (P=0.03) mRNA were greater in HFAT in the recovery period from SS exercise compared with HCHO. p70S6K activity was higher (P=0.08) at 3 h post-SS exercise in HCHO versus HFAT (72.7 ± 51.9 vs 44.7 ± 27 fmol.min mg). CONCLUSION: Post-exercise high fat feeding does not augment mRNA expression of genes associated with regulatory roles in mitochondrial biogenesis though it does increase lipid gene expression. However, post-exercise p70S6K1 activity is reduced under conditions of high fat feeding thus potentially impairing skeletal muscle remodelling processes.
|Additional Information:||This is a non-final version of an article published in final form in Hammond, Kelly M; Impey, Samuel G; Currell, Kevin; Mitchell, Nigel; Shepherd, Sam O; Jeromson, Stewart; Hawley, John A; Close, Graeme L; Hamilton, D. Lee; Sharples, Adam P; Morton, James P. Postexercise High-Fat Feeding Supresses p70S6K1 Activity in Human Skeletal Muscle. Medicine and Science in Sports and Exercise. (C) 2016 American College of Sports Medicine|
|Uncontrolled Keywords:||1106 Human Movement And Sports Science|
|Subjects:||R Medicine > RC Internal medicine > RC1200 Sports Medicine|
|Divisions:||Sport & Exercise Sciences|
|Publisher:||American College of Sports Medicine|
|Date Deposited:||21 Jul 2016 12:11|
|Last Modified:||21 Jul 2016 12:11|
|DOI or Identification number:||10.1249/MSS.0000000000001009|
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