| Title: |
Metabolic demands and replenishment of muscle glycogen after a rugby league match simulation protocol. |
| Authors: |
Bradley, WJ; Hannon, MP; Benford, V; Morehen, JC; Twist, C; Shepherd, SO; Cocks, MS; Impey, SG; Cooper, RG; Morton, JP; Close, GL |
| Publisher Information: |
Elsevier |
| Publication Year: |
2017 |
| Collection: |
Liverpool John Moores University: LJMU Research Online |
| Subject Terms: |
TX341 Nutrition. Foods and food supply; QP Physiology; RC1200 Sports Medicine |
| Description: |
OBJECTIVES: The metabolic requirements of a rugby league match simulation protocol and the timing of carbohydrate provision on glycogen re-synthesis in damaged muscle were examined. DESIGN: Fifteen (mean±SD: age 20.9±2.9 year, body-mass 87.3±14.1kg, height 177.4±6.0cm) rugby league (RL) players consumed a 6gkgday-1 CHO diet for 7-days, completed a time to exhaustion test (TTE) and a glycogen depletion protocol on day-3, a RL simulated-match protocol (RLMSP) on day-5 and a TTE on day-7. Players were prescribed an immediate or delayed (2-h-post) re-feed post-simulation. METHODS: Muscle biopsies and blood samples were obtained post-depletion, before and after simulated match-play, and 48-h after match-play with PlayerLoad and heart-rate collected throughout the simulation. Data were analysed using effects sizes±90% CI and magnitude-based inferences. RESULTS: PlayerLoad (8.0±0.7 AUmin-1) and %HRpeak (83±4.9%) during the simulation were similar to values reported for RL match-play. Muscle glycogen very likely increased from immediately after to 48-h post-simulation (272±97 cf. 416±162mmolkg-1d.w.; ES±90%CI) after immediate re-feed, but changes were unclear (283±68 cf. 361±144mmolkg-1d.w.; ES±90%CI) after delayed re-feed. CK almost certainly increased by 77.9±25.4% (0.75±0.19) post-simulation for all players. CONCLUSIONS: The RLMSP presents a replication of the internal loads associated with professional RL match-play, although difficulties in replicating the collision reduced the metabolic demands and glycogen utilisation. Further, it is possible to replete muscle glycogen in damaged muscle employing an immediate re-feed strategy. |
| Document Type: |
article in journal/newspaper |
| File Description: |
text |
| Language: |
English |
| ISSN: |
1878-1861 |
| Relation: |
https://researchonline.ljmu.ac.uk/id/eprint/6612/1/Bradley%20et%20al%20%282017%29.pdf; Bradley, WJ, Hannon, MP, Benford, V, Morehen, JC, Twist, C, Shepherd, SO, Cocks, MS, Impey, SG, Cooper, RG, Morton, JP and Close, GL (2017) Metabolic demands and replenishment of muscle glycogen after a rugby league match simulation protocol. Journal of Science and Medicine in Sport. ISSN 1878-1861 |
| DOI: |
10.1016/j.jsams.2017.02.005 |
| Availability: |
https://researchonline.ljmu.ac.uk/id/eprint/6612/; https://researchonline.ljmu.ac.uk/id/eprint/6612/1/Bradley%20et%20al%20%282017%29.pdf; https://doi.org/10.1016/j.jsams.2017.02.005 |
| Rights: |
cc_by_nc_nd |
| Accession Number: |
edsbas.E765A118 |
| Database: |
BASE |