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Completed

NCT Number: NCT03404947

Substrate Metabolism During Exercise Following Ingestion of Ethanol

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.

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Key information

Conditions

Exercise Metabolism Following Ethanol Ingestion Behavior Motor Activity

Age range

18 year–30 year

Sex eligibility

Male

Study type

Interventional

Phase

Not applicable

Primary location

University of Bath

Bath, Somerset, BA2 7AY, United Kingdom

About this study

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.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

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)

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)

Treatment and study plan

Ethanol

Dietary Supplement

For one exercise session, participants will be asked to ingest a quantity of ethanol (in the form of vodka) sufficient to maximally stimulate liver alcohol metabolism.

Primary outcomes

  1. Change in muscle glycogen content

    Time frame: Change in muscle glycogen content over 2 hours of moderate intensity cycling exercise

    Muscle biopsy and subsequent biochemical analysis

  2. Blood glucose concentration

    Time frame: 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.

  3. Blood non-esterified fatty acid (NEFA) concentration

    Time frame: 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.

Secondary outcomes

  1. Blood ethanol concentration

    Time frame: 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.

  2. Blood lactate concentration

    Time frame: 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.

  3. Carbohydrate Oxidation

    Time frame: 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.

  4. Fat Oxidation

    Time frame: 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.

Sponsors and collaborators

Lead sponsor

University of Bath

Other

Registry information

Official study title

Substrate Metabolism During 2 Hours of Moderate Intensity Exercise Following Ingestion of Ethanol in Man

Important dates

Study start
2017
Primary completion
2018
Study completion
2018
First posted
Jan 19, 2018
Registry last updated
Mar 6, 2019

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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