PMID- 31364768 OWN - NLM STAT- MEDLINE DCOM- 20200814 LR - 20200814 IS - 1469-7793 (Electronic) IS - 0022-3751 (Linking) VI - 597 IP - 18 DP - 2019 Sep TI - Post-exercise carbohydrate and energy availability induce independent effects on skeletal muscle cell signalling and bone turnover: implications for training adaptation. PG - 4779-4796 LID - 10.1113/JP278209 [doi] AB - KEY POINTS: Reduced carbohydrate (CHO) availability before and after exercise may augment endurance training-induced adaptations of human skeletal muscle, as mediated via modulation of cell signalling pathways. However, it is not known whether such responses are mediated by CHO restriction, energy restriction or a combination of both. In recovery from a twice per day training protocol where muscle glycogen concentration is maintained within 200-350 mmol kg(-1) dry weight (dw), we demonstrate that acute post-exercise CHO and energy restriction (i.e. < 24 h) does not potentiate potent cell signalling pathways that regulate hallmark adaptations associated with endurance training. In contrast, consuming CHO before, during and after an acute training session attenuated markers of bone resorption, effects that are independent of energy availability. Whilst the enhanced muscle adaptations associated with CHO restriction may be regulated by absolute muscle glycogen concentration, the acute within-day fluctuations in CHO availability inherent to twice per day training may have chronic implications for bone turnover. ABSTRACT: We examined the effects of post-exercise carbohydrate (CHO) and energy availability (EA) on potent skeletal muscle cell signalling pathways (regulating mitochondrial biogenesis and lipid metabolism) and indicators of bone metabolism. In a repeated measures design, nine males completed a morning (AM) and afternoon (PM) high-intensity interval (HIT) (8 x 5 min at 85% V̇O2peak ) running protocol (interspersed by 3.5 h) under dietary conditions of (1) high CHO availability (HCHO: CHO approximately 12 g kg(-1) , EA approximately 60 kcal kg(-1) fat free mass (FFM)), (2) reduced CHO but high fat availability (LCHF: CHO approximately 3 ((-1) , EA approximately 60 kcal kg(-1) FFM) or (3), reduced CHO and reduced energy availability (LCAL: CHO approximately 3 g kg(-1) , EA approximately 20 kcal kg(-1) FFM). Muscle glycogen was reduced to approximately 200 mmol kg(-1) dw in all trials immediately post PM HIT (P < 0.01) and remained lower at 17 h (171, 194 and 316 mmol kg(-1) dw) post PM HIT in LCHF and LCAL (P < 0.001) compared to HCHO. Exercise induced comparable p38MAPK phosphorylation (P < 0.05) immediately post PM HIT and similar mRNA expression (all P < 0.05) of PGC-1alpha, p53 and CPT1 mRNA in HCHO, LCHF and LCAL. Post-exercise circulating betaCTX was lower in HCHO (P < 0.05) compared to LCHF and LCAL whereas exercise-induced increases in IL-6 were larger in LCAL (P < 0.05) compared to LCHF and HCHO. In conditions where glycogen concentration is maintained within 200-350 mmol kg(-1) dw, we conclude post-exercise CHO and energy restriction (i.e. < 24 h) does not potentiate cell signalling pathways that regulate hallmark adaptations associated with endurance training. In contrast, consuming CHO before, during and after HIT running attenuates bone resorption, effects that are independent of energy availability and circulating IL-6. CI - (c) 2019 The Authors. The Journal of Physiology (c) 2019 The Physiological Society. FAU - Hammond, Kelly M AU - Hammond KM AD - Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Tom Reilly Building, Byrom St Campus, Liverpool, L3 3AF, UK. FAU - Sale, Craig AU - Sale C AUID- ORCID: 0000-0002-5816-4169 AD - Musculoskeletal Physiology Research Group, Sport, Health and Performance Enhancement Research Centre, School of Science and Technology, Nottingham Trent University, UK. FAU - Fraser, William AU - Fraser W AD - Norwich Medical School, University of East Anglia, Norfolk and Norwich University Hospital, Norfolk, NR4 7UY, UK. FAU - Tang, Jonathan AU - Tang J AD - Norwich Medical School, University of East Anglia, Norfolk and Norwich University Hospital, Norfolk, NR4 7UY, UK. FAU - Shepherd, Sam O AU - Shepherd SO AUID- ORCID: 0000-0001-6292-1356 AD - Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Tom Reilly Building, Byrom St Campus, Liverpool, L3 3AF, UK. FAU - Strauss, Juliette A AU - Strauss JA AUID- ORCID: 0000-0001-7175-2494 AD - Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Tom Reilly Building, Byrom St Campus, Liverpool, L3 3AF, UK. FAU - Close, Graeme L AU - Close GL AD - Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Tom Reilly Building, Byrom St Campus, Liverpool, L3 3AF, UK. FAU - Cocks, Matt AU - Cocks M AUID- ORCID: 0000-0003-1671-8714 AD - Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Tom Reilly Building, Byrom St Campus, Liverpool, L3 3AF, UK. FAU - Louis, Julien AU - Louis J AD - Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Tom Reilly Building, Byrom St Campus, Liverpool, L3 3AF, UK. FAU - Pugh, Jamie AU - Pugh J AUID- ORCID: 0000-0002-5930-4709 AD - Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Tom Reilly Building, Byrom St Campus, Liverpool, L3 3AF, UK. FAU - Stewart, Claire AU - Stewart C AUID- ORCID: 0000-0002-8104-4819 AD - Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Tom Reilly Building, Byrom St Campus, Liverpool, L3 3AF, UK. FAU - Sharples, Adam P AU - Sharples AP AUID- ORCID: 0000-0003-1526-9400 AD - Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Tom Reilly Building, Byrom St Campus, Liverpool, L3 3AF, UK. FAU - Morton, James P AU - Morton JP AUID- ORCID: 0000-0003-2776-2542 AD - Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Tom Reilly Building, Byrom St Campus, Liverpool, L3 3AF, UK. LA - eng PT - Journal Article PT - Research Support, Non-U.S. Gov't DEP - 20190821 PL - England TA - J Physiol JT - The Journal of physiology JID - 0266262 RN - 0 (Carbohydrates) RN - 9005-79-2 (Glycogen) RN - EC 2.7.11.24 (p38 Mitogen-Activated Protein Kinases) SB - IM CIN - J Physiol. 2020 Jan;598(2):221-223. PMID: 31803939 CIN - J Physiol. 2020 Mar;598(5):909-911. PMID: 31944294 MH - Adaptation, Physiological/*physiology MH - Adult MH - Bone Remodeling/*physiology MH - Carbohydrates/*physiology MH - Energy Metabolism/*physiology MH - Exercise/*physiology MH - Glycogen/metabolism MH - Humans MH - Lipid Metabolism/physiology MH - Male MH - Muscle, Skeletal/metabolism/*physiology MH - Organelle Biogenesis MH - Physical Endurance/physiology MH - Signal Transduction/*physiology MH - Young Adult MH - p38 Mitogen-Activated Protein Kinases/metabolism OTO - NOTNLM OT - IL-6 OT - PGC-1alpha OT - caloric restriction OT - betaCTX EDAT- 2019/08/01 06:00 MHDA- 2020/08/15 06:00 CRDT- 2019/08/01 06:00 PHST- 2019/04/26 00:00 [received] PHST- 2019/07/30 00:00 [accepted] PHST- 2019/08/01 06:00 [pubmed] PHST- 2020/08/15 06:00 [medline] PHST- 2019/08/01 06:00 [entrez] AID - 10.1113/JP278209 [doi] PST - ppublish SO - J Physiol. 2019 Sep;597(18):4779-4796. doi: 10.1113/JP278209. Epub 2019 Aug 21.