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Fell, JM, Hearris, MA, Ellis, DG, Moran, JEP, Jevons, EFP, Owens, DJ, Strauss, JA, Cocks, MS, Louis, JB, Shepherd, SO and Morton, JP (2021) Carbohydrate improves exercise capacity but does not affect subcellular lipid droplet morphology, AMPK and p53 signalling in human skeletal muscle. The Journal of Physiology. ISSN 0022-3751
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Carbohydrate improves exercise capacity but does not affect subcellular lipid droplet morphology, AMPK and p53 signalling in human skeletal muscle.pdf - Published Version Available under License Creative Commons Attribution. Download (3MB) | Preview |
Abstract
We examined the effects of carbohydrate (CHO) feeding on lipid droplet (LD) morphology, muscle glycogen utilisation and exercise‐induced skeletal muscle cell signalling. After a 36 h CHO loading protocol and pre‐exercise meal (12 and 2 g kg–1, respectively), eight trained males ingested 0, 45 or 90 g CHO h–1 during 180 min cycling at lactate threshold followed by an exercise capacity test (150% lactate threshold). Muscle biopsies were obtained pre‐ and post‐completion of submaximal exercise. Exercise decreased (P < 0.01) glycogen concentration to comparable levels (∼700 to 250 mmol kg–1 DW), though utilisation was greater in type I (∼40%) versus type II fibres (∼10%) (P < 0.01). LD content decreased in type I (∼50%) and type IIa fibres (∼30%) (P < 0.01), with greater utilisation in type I fibres (P < 0.01). CHO feeding did not affect glycogen or IMTG utilisation in type I or II fibres (all P > 0.05). Exercise decreased LD number within central and peripheral regions of both type I and IIa fibres, though reduced LD size was exclusive to type I fibres. Exercise induced (all P < 0.05) comparable AMPKThr172 (∼4‐fold), p53Ser15 (∼2‐fold) and CaMKIIThr268 phosphorylation (∼2‐fold) with no effects of CHO feeding (all P > 0.05). CHO increased exercise capacity where 90 g h–1 (233 ± 133 s) > 45 g h–1 (156 ± 66 s; P = 0.06) > 0 g h–1 (108 ± 54 s; P = 0.03). In conditions of high pre‐exercise CHO availability, we conclude CHO feeding does not influence exercise‐induced changes in LD morphology, glycogen utilisation or cell signalling pathways with regulatory roles in mitochondrial biogenesis.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | 06 Biological Sciences, 11 Medical and Health Sciences |
| Subjects: | R Medicine > RC Internal medicine > RC1200 Sports Medicine |
| Divisions: | Sport and Exercise Sciences |
| Publisher: | Wiley |
| Related URLs: | |
| Date of acceptance: | 22 March 2021 |
| Date of first compliant Open Access: | 19 May 2021 |
| Date Deposited: | 19 May 2021 11:00 |
| Last Modified: | 04 Sep 2021 05:27 |
| DOI or ID number: | 10.1113/JP281127 |
| URI: | https://researchonline.ljmu.ac.uk/id/eprint/15022 |
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