Carbohydrate Feeding Frequency, Muscle Glycogen and Exercise Capacity in Runners

Not Applicable

Completed

• Conditions: Exercise
• Interventions: Other: Regular carbohydrate feeding; Other: Single carbohydrate bolus

• Registration Number: NCT03749785
• Lead Sponsor: University of Bath

Brief Summary

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

Detailed Description

Not available

Study Timeline

• Study Start: 2018-10-14
• Study First Submitted: 2018-11-19
• Study First Submitted QC: 2018-11-20
• Study First Posted: 2018-11-21
• Status Verified: 2019-03
• Primary Completion: 2019-03-20
• Study Completion: 2019-04-16
• Last Update Submitted: 2019-10-31
• Last Update Posted: 2019-11-01

Recruitment & Eligibility

• Status: COMPLETED
• Sex: Male
• Target Recruitment: 7

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 & Design

• Study Type: INTERVENTIONAL
• Study Design: CROSSOVER

Arm && Interventions

Group	Intervention	Description
Regular carbohydrate feeding	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
Single carbohydrate bolus	Single carbohydrate bolus	Ingestion of 75 g sucrose, given in a single bolus after 75 minutes of exercise, during a time to exhaustion run

Primary Outcome Measures

Name	Time	Method
Muscle glycogen concentrations	Estimated to be between 90 and 145 minutes	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
Exercise capacity	Estimated to be between 90 and 145 minutes	Time to exhaustion at the pre-determined speed to elicit exhaustion after \~90 minutes when ingesting water only

Secondary Outcome Measures

Name	Time	Method
Ratings of perceived exertion	Estimated to be between 90 and 145 minutes	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.
Fat oxidation	Estimated to be between 90 and 145 minutes	Total fat oxidation during treadmill running. Measured using indirect calorimetry and reported in grams.
Plasma lactate concentrations	Estimated to be between 90 and 145 minutes	Plasma lactate concentrations during treadmill running. Measured using colourimetric assay and reported in mmol/L.
Rate of oxygen consumption	Estimated to be between 90 and 145 minutes	Rate of oxygen consumption during treadmill running. Measured using indirect calorimetry and reported in litres per minute
Rate of carbon dioxide production	Estimated to be between 90 and 145 minutes	Rate of carbon dioxide production during treadmill running. Measured using indirect calorimetry and reported in litres per minute.
Ratings of stomach discomfort	Estimated to be between 90 and 145 minutes	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
Carbohydrate oxidation	Estimated to be between 90 and 145 minutes	Total carbohydrate oxidation during treadmill running. Measured using indirect calorimetry and reported in grams.
Plasma glucose concentrations	Estimated to be between 90 and 145 minutes	Plasma lactate concentrations during of treadmill running. Measured using colourimetric assay and reported in mmol/L
Heart rate	Estimated to be between 90 and 145 minutes	Heart rate during treadmill running measured by telemetry and reported in beats per minute

Trial Locations

Locations (1)

Department for Health, University of Bath; 🇬🇧 Bath, United Kingdom