Substrate Metabolism During Exercise Following Ingestion of Ethanol

Not Applicable

Completed

• Conditions: Exercise Metabolism Following Ethanol Ingestion
• Interventions: Dietary Supplement: Ethanol

• Registration Number: NCT03404947
• Lead Sponsor: University of Bath

Brief Summary

This study will investigate how ethanol (pure alcohol) influences carbohydrate and fat metabolism during prolonged, moderate intensity exercise. Participants will perform two bouts of cycling exercise with or without prior ingestion of ethanol, in a randomised order, separated by one week.

Detailed Description

Very little research has investigated the influence of ethanol on metabolism during prolonged exercise. Evidence suggests that delivery of fat to the working muscles during exercise may be limited with ethanol and therefore this may shift the relative proportions of energy derived from muscle stores of carbohydrate as a result (Jorfeldt \& Juhlin-Dannfelt, 1976).

The current study aims to investigate how a small-moderate dose of ethanol influences where energy is derived from during a prolonged bout of moderate intensity cycling exercise.

Participants will visit the lab on three occasions, once for preliminary measurements of fitness and body composition, and twice for the experimental bouts of exercise. Body composition will be assessed using a dual-energy x-ray absorptiometry (DEXA) scan, which will measure lean mass, fat mass, and bone mineral density. Participants will then perform an incremental maximal oxygen uptake test to determine intensity for the experimental bouts of exercise.

The two experimental bouts of exercise include cycling on an exercise bike for 2 hours at 55% of their maximal oxygen uptake (i.e. fitness) following 1 hours rest. This will be performed under two conditions: with and without ethanol ingestion. Pre and post exercise muscle biopsies will be collected to assess muscle metabolism, with regular blood samples and expired breath samples being collected to further investigate fuel delivery and use by the working tissues. The experimental bouts of exercise will be performed 1 week apart in a randomised order.

Basic Information
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Recruitment & Eligibility
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Study & Design
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Trial Locations

Study Timeline

• Study Start: 2017-11-13
• Study First Submitted: 2017-12-05
• Study First Submitted QC: 2018-01-18
• Study First Posted: 2018-01-19
• Primary Completion: 2018-06-29
• Study Completion: 2018-06-29
• Status Verified: 2019-03
• Last Update Submitted: 2019-03-05
• Last Update Posted: 2019-03-06

Recruitment & Eligibility

• Status: COMPLETED
• Sex: Male
• Target Recruitment: 8

Inclusion Criteria

• Habitual alcohol consumer (average 1-14 units per week)
• BMI 18.5 - 29.9 kg/m2
• Be able to attend the laboratory and willing to participate in necessary protocols
• Be willing to undertake the durations of the exercise protocol (2 hours) ]
• Have the capacity and willingness to provide informed consent (oral and written)

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Exclusion Criteria

• Non-or excessive alcohol drinkers (0 or >14 units per week)
• History of substance abuse
• Habitual/previously habitual smokers
• BMI >30.0 kg/m2
• Experience contraindications to the administration of the proposed anaesthetic (Lidocaine Hydrochloride)

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Study & Design

• Study Type: INTERVENTIONAL
• Study Design: CROSSOVER

Arm && Interventions

Group	Intervention	Description
Ethanol	Ethanol	Participants will ingest ethanol (in the form of 40% ethanol) at an ingestion rate of 0.1 grams/kg lean body mass/hour in a solution with water.

Primary Outcome Measures

Name	Time	Method
Change in muscle glycogen content	Change in muscle glycogen content over 2 hours of moderate intensity cycling exercise	Muscle biopsy and subsequent biochemical analysis
Blood non-esterified fatty acid (NEFA) concentration	Blood samples will be taken every 15 minutes during rest and the first hour of exercise, they will be taken every 30 minutes in the second hour of exercise.	Venous blood samples will be taken and biochemically analysed for NEFA concentration.
Blood glucose concentration	Blood samples will be taken every 15 minutes during rest and the first hour of exercise, they will be taken every 30 minutes in the second hour of exercise.	Venous blood samples will be taken and biochemically analysed for blood glucose concentration.

Secondary Outcome Measures

Name	Time	Method
Blood lactate concentration	Blood samples will be taken every 15 minutes during rest and the first hour of exercise, they will be taken every 30 minutes in the second hour of exercise.	Venous blood samples will be taken and biochemically analysed for blood lactate concentration.
Carbohydrate Oxidation	Expired breath samples will be collected at baseline before beverage consumption and again after 1 hours rest. Samples will collected every 15 minutes during the first hour of exercise and every 30 minutes during the second hour	Carbohydrate oxidation will be determined through indirect calorimetry via the douglas bag technique.
Fat Oxidation	Expired breath samples will be collected at baseline before beverage consumption and again after 1 hours rest. Samples will collected every 15 minutes during the first hour of exercise and every 30 minutes during the second hour	Fat oxidation will be determined through indirect calorimetry via the douglas bag technique.
Blood ethanol concentration	Blood samples will be taken every 15 minutes during rest and the first hour of exercise, they will be taken every 30 minutes in the second hour of exercise.	Venous blood samples will be taken and biochemically analysed for blood ethanol concentration.

Trial Locations

Locations (1)

University of Bath; 🇬🇧 Bath, Somerset, United Kingdom