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J Appl Physiol (1985). 2015 Sep 15;119(6):643-55. doi: 10.1152/japplphysiol.00857.2014. Epub 2015 Jun 25.

Effects of sleeping with reduced carbohydrate availability on acute training responses.

Author information

1
Exercise and Nutrition Research Group, School of Medical Sciences, RMIT University, Bundoora, Australia;
2
Centre for Exercise and Nutrition, Mary MacKillop Health Research Institute, Australian Catholic University, Melbourne, Australia;
3
Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden;
4
National Sports Institute of Malaysia, Kuala Lumpur, Malaysia;
5
Sports Nutrition, Australian Institute of Sport, Belconnen, Australia;
6
Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden; and.
7
Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden; Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden; and.
8
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.

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.

KEYWORDS:

HIT; cycling; muscle glycogen; sleep-low; train low

PMID:
26112242
DOI:
10.1152/japplphysiol.00857.2014
[Indexed for MEDLINE]
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