Carbohydrate Feeding Frequency, Muscle Glycogen and Exercise Capacity in Runners

The Effect of Carbohydrate Feeding Frequency on Muscle Glycogen and Exercise Capacity in Runners

The aim of this study is to investigate the effects of regular sucrose feeds compared to a single large bolus given late in exercise, on muscle glycogen utilisation, exercise capacity and other markers of metabolism during running

Study Overview

• Status: Completed
• Conditions: Exercise
• Intervention / Treatment: Other: Regular carbohydrate feeding; Other: Single carbohydrate bolus

• Study Type: Interventional
• Enrollment (Actual): 7
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United Kingdom
  • Bath, United Kingdom, BA2 7AY
    • Department for Health, University of Bath

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 50 years (Adult)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: Male

Description

Inclusion Criteria:

• Self-identify as a trained runner
• Regularly participate in running activity (>2 times a week)
• Participated in running based training for a minimum of 2 years
• Be willing to undertake exercise sessions until volitional exhaustion
• Be willing to have the necessary samples taken during the testing protocols
• Not a habitual smoker
• Have the capacity and willingness to provide informed consent (oral and written)
• Successful completion of the physical activity readiness questionnaire (PAR-Q)

Exclusion Criteria:

• Female
• <18 or >50 years old
• Not regularly participating in running activity (<3 times a week)
• Experience contraindications to the administration of the proposed anaesthetic (Lidocaine Hydrochloride)
• Habitual/previously habitual smoker

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Regular carbohydrate feeding; Ingestion of 75 g sucrose, given in regular doses for the first 75 minutes of exercise during a time to exhaustion run	Other: Regular carbohydrate feeding; 60 ml of water with 5 g sucrose given every 5 minutes 14 times up until 70 minutes followed by 5 g sucrose after 75 minutes in a 250 ml solution
Active Comparator: Single carbohydrate bolus; Ingestion of 75 g sucrose, given in a single bolus after 75 minutes of exercise, during a time to exhaustion run	Other: Single carbohydrate bolus; 60 ml of water given every 5 minutes 14 times up until 70 minutes followed by 75 g sucrose after 75 minutes in a 250 ml solution

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Muscle glycogen concentrations	Muscle glycogen concentration at rest, after 75 minutes of treadmill running and at volitional exhaustion. Measured using the bergstrom needle technique for obtaining muscle biopsy samples	Estimated to be between 90 and 145 minutes
Exercise capacity	Time to exhaustion at the pre-determined speed to elicit exhaustion after ~90 minutes when ingesting water only	Estimated to be between 90 and 145 minutes

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Ratings of perceived exertion	Subjective ratings of perceived exertion, during treadmill running. Measured using a borg scale of 6 to 20, where 6 = no exertion at all, and 20 = maximal exertion.	Estimated to be between 90 and 145 minutes
Ratings of stomach discomfort	Subjective ratings of stomach discomfort during treadmill running. Measured using a modified borg scale of 6 to 20, where 6 = no discomfort and 20 = maximal discomfort	Estimated to be between 90 and 145 minutes
Carbohydrate oxidation	Total carbohydrate oxidation during treadmill running. Measured using indirect calorimetry and reported in grams.	Estimated to be between 90 and 145 minutes
Fat oxidation	Total fat oxidation during treadmill running. Measured using indirect calorimetry and reported in grams.	Estimated to be between 90 and 145 minutes
Plasma glucose concentrations	Plasma lactate concentrations during of treadmill running. Measured using colourimetric assay and reported in mmol/L	Estimated to be between 90 and 145 minutes
Plasma lactate concentrations	Plasma lactate concentrations during treadmill running. Measured using colourimetric assay and reported in mmol/L.	Estimated to be between 90 and 145 minutes
Heart rate	Heart rate during treadmill running measured by telemetry and reported in beats per minute	Estimated to be between 90 and 145 minutes
Rate of oxygen consumption	Rate of oxygen consumption during treadmill running. Measured using indirect calorimetry and reported in litres per minute	Estimated to be between 90 and 145 minutes
Rate of carbon dioxide production	Rate of carbon dioxide production during treadmill running. Measured using indirect calorimetry and reported in litres per minute.	Estimated to be between 90 and 145 minutes

Collaborators and Investigators

• Sponsor: University of Bath

Study record dates

Study Major Dates

• Study Start (Actual): October 14, 2018
• Primary Completion (Actual): March 20, 2019
• Study Completion (Actual): April 16, 2019

Study Registration Dates

• First Submitted: November 19, 2018
• First Submitted That Met QC Criteria: November 20, 2018
• First Posted (Actual): November 21, 2018

Study Record Updates

• Last Update Posted (Actual): November 1, 2019
• Last Update Submitted That Met QC Criteria: October 31, 2019
• Last Verified: March 1, 2019

More Information

Terms related to this study

• Other Study ID Numbers: 18/SW/0177

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No