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Postexercise high-fat feeding suppresses p70S6K1 activity in human skeletal muscle
journal contribution
posted on 2016-11-01, 00:00 authored by Kelly M Hammond, Samuel G Impey, Kevin Currell, Nigel Mitchell, Sam O Shepherd, Stewart Jeromson, John A Hawley, Graeme L Close, Lee HamiltonLee Hamilton, Adam P Sharples, James P MortonPURPOSE: This study aimed to examine the effects of reduced CHO but high postexercise fat availability on cell signaling and expression of genes with putative roles in regulation of mitochondrial biogenesis, lipid metabolism, and muscle protein synthesis. METHODS: Ten males completed a twice per day exercise model (3.5 h between sessions) comprising morning high-intensity interval training (8 × 5 min at 85% V˙O2peak) and afternoon steady-state (SS) running (60 min at 70% V˙O2peak). In a repeated-measures design, runners exercised under different isoenergetic dietary conditions consisting of high-CHO (HCHO: 10 g·kg CHO, 2.5 g·kg protein, and 0.8 g·kg fat for the entire trial period) or reduced-CHO but high-fat availability in the postexercise recovery periods (HFAT: 2.5 g·kg CHO, 2.5 g·kg protein, and 3.5 g·kg fat for the entire trial period). RESULTS: Muscle glycogen was lower (P < 0.05) at 3 h (251 vs 301 mmol·kg dry weight) and 15 h (182 vs 312 mmol·kg dry weight) post-SS exercise in HFAT compared with HCHO. Adenosine monophosphate-activated protein kinase α2 activity was not increased post-SS in either condition (P = 0.41), although comparable increases (all P < 0.05) in PGC-1α, p53, citrate synthase, Tfam, peroxisome proliferator-activated receptor, and estrogen-related receptor α mRNA were observed in HCHO and HFAT. By contrast, PDK4 (P = 0.003), CD36 (P = 0.05), and carnitine palmitoyltransferase 1 (P = 0.03) mRNA were greater in HFAT in the recovery period from SS exercise compared with HCHO. Ribosomal protein S6 kinase 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: Postexercise high-fat feeding does not augment the mRNA expression of genes associated with regulatory roles in mitochondrial biogenesis, although it does increase lipid gene expression. However, postexercise ribosomal protein S6 kinase 1 activity is reduced under conditions of high-fat feeding, thus potentially impairing skeletal muscle remodeling processes.
History
Journal
Medicine and science in sports and exerciseVolume
48Issue
11Pagination
2108 - 2117Publisher
Lippincott, Williams & WilkinsLocation
Philadelphia, Pa.Publisher DOI
ISSN
0195-9131eISSN
1530-0315Language
engPublication classification
C1 Refereed article in a scholarly journalCopyright notice
2016, the American College of Sports MedicineUsage metrics
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No categories selectedKeywords
Dietary CarbohydratesDietary FatsExerciseGene ExpressionLipid MetabolismMuscle ProteinsMuscle, SkeletalOrganelle BiogenesisRibosomal Protein S6 KinasesSignal TransductionAMPK-α2PGC-1αp53glycogenmitochondrial biogenesisScience & TechnologyLife Sciences & BiomedicineSport SciencesAMPK-alpha 2PGC-1 alphaREDUCED CARBOHYDRATE AVAILABILITYHIGH-INTENSITY INTERVALSHORT-TERMAMINO-ACIDINDUCED ACTIVATIONGENE-EXPRESSIONMETABOLIC GENESMESSENGER-RNAADAPTATION
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