Initiating aerobic exercise with low glycogen content reduces markers of myogenesis but not mTORC1 signaling.

Autor: Margolis LM; Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, 10 General Greene Avenue, Bldg. 42, Natick, MA, 01760, USA. lee.m.margolis.civ@mail.mil., Wilson MA; Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, 10 General Greene Avenue, Bldg. 42, Natick, MA, 01760, USA., Whitney CC; Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, 10 General Greene Avenue, Bldg. 42, Natick, MA, 01760, USA., Carrigan CT; Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, 10 General Greene Avenue, Bldg. 42, Natick, MA, 01760, USA., Murphy NE; Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, 10 General Greene Avenue, Bldg. 42, Natick, MA, 01760, USA., Hatch-McChesney A; Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, 10 General Greene Avenue, Bldg. 42, Natick, MA, 01760, USA., Pasiakos SM; Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, 10 General Greene Avenue, Bldg. 42, Natick, MA, 01760, USA.
Jazyk: angličtina
Zdroj: Journal of the International Society of Sports Nutrition [J Int Soc Sports Nutr] 2021 Jul 10; Vol. 18 (1), pp. 56. Date of Electronic Publication: 2021 Jul 10.
DOI: 10.1186/s12970-021-00455-z
Abstrakt: Background: The effects of low muscle glycogen on molecular markers of protein synthesis and myogenesis before and during aerobic exercise with carbohydrate ingestion is unclear. The purpose of this study was to determine the effects of initiating aerobic exercise with low muscle glycogen on mTORC1 signaling and markers of myogenesis.
Methods: Eleven men completed two cycle ergometry glycogen depletion trials separated by 7-d, followed by randomized isocaloric refeeding for 24-h to elicit low (LOW; 1.5 g/kg carbohydrate, 3.0 g/kg fat) or adequate (AD; 6.0 g/kg carbohydrate, 1.0 g/kg fat) glycogen. Participants then performed 80-min of cycle ergometry (64 ± 3% VO 2peak ) while ingesting 146 g carbohydrate. mTORC1 signaling (Western blotting) and gene transcription (RT-qPCR) were determined from vastus lateralis biopsies before glycogen depletion (baseline, BASE), and before (PRE) and after (POST) exercise.
Results: Regardless of treatment, p-mTORC1 Ser2448 , p-p70S6K Ser424/421 , and p-rpS6 Ser235/236 were higher (P < 0.05) POST compared to PRE and BASE. PAX7 and MYOGENIN were lower (P < 0.05) in LOW compared to AD, regardless of time, while MYOD was lower (P < 0.05) in LOW compared to AD at PRE, but not different at POST.
Conclusion: Initiating aerobic exercise with low muscle glycogen does not affect mTORC1 signaling, yet reductions in gene expression of myogenic regulatory factors suggest that muscle recovery from exercise may be reduced.
(© 2021. The Author(s).)
Databáze: MEDLINE
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