Effects of sleeping with reduced carbohydrate availability on acute training responses

Jun 27, 2015Journal of applied physiology (Bethesda, Md. : 1985)

How Sleeping with Low Carbohydrate Levels Affects Immediate Training Responses

AI simplified

Circadian Biology on OpenScience ↗PubMed ↗DOI ↗

Abstract

Muscle glycogen levels were higher in the FED condition at all times post-high-intensity training.

Both fasting and fed conditions increased mRNA levels of markers associated with muscle adaptation after prolonged exercise.
Fasted conditions resulted in greater elevations of PDK4 mRNA compared to fed conditions.
Resting levels of certain proteins involved in energy regulation were higher in the fasted state.
Fat oxidation during exercise was greater in the fasted group, linked to increased expression of specific metabolic genes.
DNA methylation changes were observed for genes related to metabolism, with differing responses depending on feeding conditions.

AI simplified

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.

Full Text

Full text is available at the source.

View full text ↗

Effects of sleeping with reduced carbohydrate availability on acute training responses

Abstract

Full Text

You found one interesting study. We’ll send the next 7.

what lands in your inbox each week:

Recent issues from the circadian biology brief

Abstract

Full Text

Related papers

You found one interesting study. We’ll send the next 7.

what lands in your inbox each week:

Recent issues from the circadian biology brief