Full Text Available

Access Repository
Note: Clicking the button above will open the full text document at the original institutional repository in a new window.
Cover Image

Limits to exogenous glucose oxidation by skeletal muscle during prolonged, moderate-intensity exercise in man

Several factors may determine the rate. at which exogenous carbohydrate (CHO) is utilised by the human working muscles during prolonged (> 90 min moderate-intensity (63% of peak sustained power output [PPO]) exercise. These include i) the rate of gastric emptying of an ingested fluid, ii) the rate o...

Full description

Saved in:
Main Author: Hawley, John Alan
Other Authors: Noakes, Timothy D
Format: Thesis
Language:English
Published: MRC/UCT RU for Exercise and Sport Medicine 2018
Subjects:
Exercise - physiology
Glucose - Metabolism
Medical Physiology
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1867613236305592321
access_status_str Open Access
author Hawley, John Alan
author2 Noakes, Timothy D
author_browse Hawley, John Alan
Noakes, Timothy D
author_facet Noakes, Timothy D
Hawley, John Alan
author_sort Hawley, John Alan
collection Thesis
description Several factors may determine the rate. at which exogenous carbohydrate (CHO) is utilised by the human working muscles during prolonged (> 90 min moderate-intensity (63% of peak sustained power output [PPO]) exercise. These include i) the rate of gastric emptying of an ingested fluid, ii) the rate of digestion, absorption and subsequent transport of glucose into the systemic circulation, and iii) the rate of glucose uptake and oxidation by the working muscles. To test the hypothesis that the rate of gastric emptying is the primary factor limiting the rate of CHO delivery to the working muscles during exercise, uniformly labelled ¹⁴carbon (U-¹⁴C) tracer techniques were used in association with conventional gas exchange measurements and post-exercise gastric aspiration to compare the rates of gastric emptying, intestinal CHO delivery and ingested CHO oxidation from 15 g/100 ml solutions of glucose, maltose, a 22 chain-length glucose polymer, and an isocaloric 'soluble' starch preparation. Two groups of six highly-trained male cyclists or triathletes each ingested two of the test drinks which were given as a 400 ml loading bolus immediately before and then as eight 100 ml feedings at 10 min intervals during 90 min of continuous cycling at a work rate of 63% of PPO (~70% of maximal oxygen consumption [VO₂ₘₐₓ]).
format Thesis
id oai:open.uct.ac.za:11427/27121
institution University of Cape Town (South Africa)
language eng
last_indexed 2026-06-10T12:32:56.154Z
license_str Not specified — see source repository
provenance_str_mv Harvested via OAI-PMH from UCTD — University of Cape Town Open Access Repository
publishDate 2018
publishDateRange 2018
publishDateSort 2018
publisher MRC/UCT RU for Exercise and Sport Medicine
publisherStr MRC/UCT RU for Exercise and Sport Medicine
record_format dspace
source_str UCTD — University of Cape Town Open Access Repository
spelling oai:open.uct.ac.za:11427/27121 Limits to exogenous glucose oxidation by skeletal muscle during prolonged, moderate-intensity exercise in man Hawley, John Alan Noakes, Timothy D Dennis, Steve Exercise - physiology Glucose - Metabolism Medical Physiology Several factors may determine the rate. at which exogenous carbohydrate (CHO) is utilised by the human working muscles during prolonged (> 90 min moderate-intensity (63% of peak sustained power output [PPO]) exercise. These include i) the rate of gastric emptying of an ingested fluid, ii) the rate of digestion, absorption and subsequent transport of glucose into the systemic circulation, and iii) the rate of glucose uptake and oxidation by the working muscles. To test the hypothesis that the rate of gastric emptying is the primary factor limiting the rate of CHO delivery to the working muscles during exercise, uniformly labelled ¹⁴carbon (U-¹⁴C) tracer techniques were used in association with conventional gas exchange measurements and post-exercise gastric aspiration to compare the rates of gastric emptying, intestinal CHO delivery and ingested CHO oxidation from 15 g/100 ml solutions of glucose, maltose, a 22 chain-length glucose polymer, and an isocaloric 'soluble' starch preparation. Two groups of six highly-trained male cyclists or triathletes each ingested two of the test drinks which were given as a 400 ml loading bolus immediately before and then as eight 100 ml feedings at 10 min intervals during 90 min of continuous cycling at a work rate of 63% of PPO (~70% of maximal oxygen consumption [VO₂ₘₐₓ]). 2018-01-30T13:37:58Z 2018-01-30T13:37:58Z 1993 Doctoral Thesis Doctoral PhD http://hdl.handle.net/11427/27121 eng application/pdf MRC/UCT RU for Exercise and Sport Medicine Faculty of Health Sciences University of Cape Town
spellingShingle Exercise - physiology
Glucose - Metabolism
Medical Physiology
Hawley, John Alan
Limits to exogenous glucose oxidation by skeletal muscle during prolonged, moderate-intensity exercise in man
thesis_degree_str Doctoral
title Limits to exogenous glucose oxidation by skeletal muscle during prolonged, moderate-intensity exercise in man
title_full Limits to exogenous glucose oxidation by skeletal muscle during prolonged, moderate-intensity exercise in man
title_fullStr Limits to exogenous glucose oxidation by skeletal muscle during prolonged, moderate-intensity exercise in man
title_full_unstemmed Limits to exogenous glucose oxidation by skeletal muscle during prolonged, moderate-intensity exercise in man
title_short Limits to exogenous glucose oxidation by skeletal muscle during prolonged, moderate-intensity exercise in man
title_sort limits to exogenous glucose oxidation by skeletal muscle during prolonged moderate intensity exercise in man
topic Exercise - physiology
Glucose - Metabolism
Medical Physiology
url http://hdl.handle.net/11427/27121
work_keys_str_mv AT hawleyjohnalan limitstoexogenousglucoseoxidationbyskeletalmuscleduringprolongedmoderateintensityexerciseinman

Similar Items