Clinical trial NCT03404947: Substrate Metabolism During Exercise Following Ingestion of Ethanol
Official title: Substrate Metabolism During 2 Hours of Moderate Intensity Exercise Following Ingestion of Ethanol in Man
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Exercise Metabolism Following Ethanol Ingestion
Keywords: Exercise
Metabolism
Nutrition
Lead sponsor: University of Bath
Sponsor class: OTHER
First posted: 2018-01-19
Enrollment: 8
Sex: MALE
Minimum age (years): 18
Maximum age (years): 30
Standard ages: ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: CROSSOVER
Primary purpose: BASIC_SCIENCE

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.

Eligibility criteria: 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)

Primary outcomes:
measure: Change in muscle glycogen content
timeFrame: Change in muscle glycogen content over 2 hours of moderate intensity cycling exercise
measure: Blood glucose concentration
timeFrame: 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.
measure: Blood non-esterified fatty acid (NEFA) concentration
timeFrame: 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.
Secondary outcomes:
measure: Blood ethanol concentration
timeFrame: 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.
measure: Blood lactate concentration
timeFrame: 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.
measure: Carbohydrate Oxidation
timeFrame: 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
measure: Fat Oxidation
timeFrame: 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
Other outcomes:
Locations:
city: Bath
country: United Kingdom
facility: University of Bath
state: Somerset
Study officials:
affiliation: University of Bath
name: Harry Smith
role: PRINCIPAL_INVESTIGATOR
affiliation: University of Bath
name: James Betts, PhD
role: PRINCIPAL_INVESTIGATOR
References:
citation: Jorfeldt L, Juhlin-Dannfelt A. The influence of ethanol on human splanchnic and skeletal muscle metabolism during exercise. Scand J Clin Lab Invest. 1977 Nov;37(7):609-18. doi: 10.3109/00365517709100653. No abstract available.
citation: Juhlin-Dannfelt A, Ahlborg G, Hagenfeldt L, Jorfeldt L, Felig P. Influence of ethanol on splanchnic and skeletal muscle substrate turnover during prolonged exercise in man. Am J Physiol. 1977 Sep;233(3):E195-202. doi: 10.1152/ajpendo.1977.233.3.E195. No abstract available.
citation: Juhlin-Dannfelt A, Jorfeldt L, Hagenfeldt L, Hulten B. Influence of ethanol on non-esterified fatty acid and carbohydrate metabolism during exercise in man. Clin Sci Mol Med. 1977 Sep;53(3):205-14. doi: 10.1042/cs0530205. No abstract available.