Exercise Metabolism Following Ethanol Ingestion Clinical Trial
Official title:
Substrate Metabolism During 2 Hours of Moderate Intensity Exercise Following Ingestion of Ethanol in Man
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.
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.
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