Document Detail


The influence of starch structure on glycogen resynthesis and subsequent cycling performance.
MedLine Citation:
PMID:  8858410     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
The present study was designed to evaluate the influence of starch structure on muscle glycogen resynthesis and cycling performance. Eight male cyclists (22 +/- 1 yr) completed an exercise protocol (DP) to decrease vastus lateralis glycogen concentration. This exercise consisted of 60 min cycling at 75% VO2max, followed by six 1-min sprints at approximately 125% VO2max with 1 min rest intervals. In the 12 hr after the exercise each subject consumed approximately 3000 kcal (65:20:15% carbohydrate, fat and protein). All of the carbohydrate (CHO) consumed was derived from one of four solutions; 1) glucose, 2) maltodextrin (glucose polymer), 3) waxy starch (100% amylopectin), or 4) resistant starch (100% amylose). Muscle biopsies were taken from the vastus lateralis muscle after DP and 24 hr later to determine glycogen concentrations. A 30 min cycling time trial (TT) was performed following the 24 hr post-DP muscle biopsy to examine the influence of the feeding regimen on total work output. The post-DP glycogen concentrations were similar among the four trials, ranging from 220.3 +/- 29.2 to 264 +/- 48.3 mmol.kg-1 dry weight (d.w.) muscle. Twenty-four hours after DP, muscle glycogen concentration had increased less (p < 0.05) in the resistant starch trial (+90.8 +/- 12.8 mmol.kg-1 d.w.) than in the glucose (+197.7 +/- 31.6 mmol.kg-1 d.w.), maltodextrin (+136.7 +/- 24.5 mmol.kg-1 d.w.) and waxy starch (+171.8 +/- 37.1 mmol.kg-1 d.w.) trials. There were no differences in total work output during the TT, or blood lactate concentration immediately following the TT in any of the CHO trials. In summary, glycogen resynthesis was attenuated following ingestion of starch with a high amylose content, relative to amylopectin or glucose; however, short duration time trial performance was unaffected.
Authors:
A C Jozsi; T A Trappe; R D Starling; B Goodpaster; S W Trappe; W J Fink; D L Costill
Publication Detail:
Type:  Clinical Trial; Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  International journal of sports medicine     Volume:  17     ISSN:  0172-4622     ISO Abbreviation:  Int J Sports Med     Publication Date:  1996 Jul 
Date Detail:
Created Date:  1997-01-13     Completed Date:  1997-01-13     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  8008349     Medline TA:  Int J Sports Med     Country:  GERMANY    
Other Details:
Languages:  eng     Pagination:  373-8     Citation Subset:  IM; S    
Affiliation:
Human Performance Laboratory, Ball State University, Muncie, Indiana 47306, USA.
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MeSH Terms
Descriptor/Qualifier:
Amylopectin / metabolism
Amylose / metabolism
Analysis of Variance
Bicycling / physiology*
Exercise / physiology*
Exercise Test
Glucose / metabolism
Glycogen / analysis,  biosynthesis*
Humans
Lactic Acid / blood
Male
Muscle, Skeletal / chemistry
Polysaccharides / metabolism
Time Factors
Chemical
Reg. No./Substance:
0/Polysaccharides; 50-21-5/Lactic Acid; 50-99-7/Glucose; 9005-79-2/Glycogen; 9005-82-7/Amylose; 9037-22-3/Amylopectin; 9050-36-6/maltodextrin

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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