title: Effects of sleeping with reduced carbohydrate availability on acute training responses.
abstract: We determined the effects of "periodized nutrition" on skeletal muscle and whole body responses to a bout of prolonged exercise the following morning. Seven cyclists completed two trials receiving isoenergetic diets differing in the timing of ingestion: they consumed either 8 g/kg body mass (BM) of carbohydrate (CHO) before undertaking an evening session of high-intensity training (HIT) and slept without eating (FASTED), or consumed 4 g/kg BM of CHO before HIT, then 4 g/kg BM of CHO before sleeping (FED). The next morning subjects completed 2 h of cycling (120SS) while overnight fasted. Muscle biopsies were taken on day 1 (D1) before and 2 h after HIT and on day 2 (D2) pre-, post-, and 4 h after 120SS. Muscle [glycogen] was higher in FED at all times post-HIT (P < 0.001). The cycling bouts increased PGC1α mRNA and PDK4 mRNA (P < 0.01) in both trials, with PDK4 mRNA being elevated to a greater extent in FASTED (P < 0.05). Resting phosphorylation of AMPK(Thr172), p38MAPK(Thr180/Tyr182), and p-ACC(Ser79) (D2) was greater in FASTED (P < 0.05). Fat oxidation during 120SS was higher in FASTED (P = 0.01), coinciding with increases in ACC(Ser79) and CPT1 as well as mRNA expression of CD36 and FABP3 (P < 0.05). Methylation on the gene promoter for COX4I1 and FABP3 increased 4 h after 120SS in both trials, whereas methylation of the PPARδ promoter increased only in FASTED. We provide evidence for shifts in DNA methylation that correspond with inverse changes in transcription for metabolically adaptive genes, although delaying postexercise feeding failed to augment markers of mitochondrial biogenesis.
authors.affiliation: Exercise and Nutrition Research Group, School of Medical Sciences, RMIT University, Bundoora, Australia;
authors.forename: Stephen C
authors.initials: SC
authors.lastname: Lane
authors.affiliation: Centre for Exercise and Nutrition, Mary MacKillop Health Research Institute, Australian Catholic University, Melbourne, Australia;
authors.forename: Donny M
authors.initials: DM
authors.lastname: Camera
authors.affiliation: Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden;
authors.forename: David Gray
authors.initials: DG
authors.lastname: Lassiter
authors.affiliation: Exercise and Nutrition Research Group, School of Medical Sciences, RMIT University, Bundoora, Australia;
authors.forename: José L
authors.initials: JL
authors.lastname: Areta
authors.affiliation: Exercise and Nutrition Research Group, School of Medical Sciences, RMIT University, Bundoora, Australia;
authors.forename: Stephen R
authors.initials: SR
authors.lastname: Bird
authors.affiliation: National Sports Institute of Malaysia, Kuala Lumpur, Malaysia;
authors.forename: Wee Kian
authors.initials: WK
authors.lastname: Yeo
authors.affiliation: Sports Nutrition, Australian Institute of Sport, Belconnen, Australia;
authors.forename: Nikki A
authors.initials: NA
authors.lastname: Jeacocke
authors.affiliation: Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden; and.
authors.forename: Anna
authors.initials: A
authors.lastname: Krook
authors.affiliation: Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden; Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden; and.
authors.forename: Juleen R
authors.initials: JR
authors.lastname: Zierath
authors.affiliation: Sports Nutrition, Australian Institute of Sport, Belconnen, Australia;
authors.forename: Louise M
authors.initials: LM
authors.lastname: Burke
authors.affiliation: Centre for Exercise and Nutrition, Mary MacKillop Health Research Institute, Australian Catholic University, Melbourne, Australia; Institute for Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, United Kingdom john.hawley@acu.edu.au.
authors.forename: John A
authors.initials: JA
authors.lastname: Hawley
mesh_terms: D055372:AMP-Activated Protein Kinases / Q000378:metabolism; D000222:Adaptation, Physiological / Q000502:physiology; D000328:Adult; D019175:DNA Methylation / Q000502:physiology; D004040:Dietary Carbohydrates / Q000378:metabolism*; D015444:Exercise / Q000502:physiology*; D006003:Glycogen / Q000378:metabolism; D006801:Humans; D008297:Male; D018482:Muscle, Skeletal / Q000378:metabolism / Q000502:physiology; D010766:Phosphorylation / Q000502:physiology; D010807:Physical Endurance / Q000502:physiology*; D011494:Protein Kinases / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D012890:Sleep / Q000502:physiology*; D048051:p38 Mitogen-Activated Protein Kinases / Q000378:metabolism
chemical_list: D004040:Dietary Carbohydrates; D012333:RNA, Messenger; D006003:Glycogen; D011494:Protein Kinases; C403287:pyruvate dehydrogenase kinase 4; D048051:p38 Mitogen-Activated Protein Kinases; D055372:AMP-Activated Protein Kinases
keywords: HIT; cycling; muscle glycogen; sleep-low; train low