Clinical trial NCT02110836: The Impact of Sucrose Ingestion During Exercise on Liver and Muscle Glycogen Concentration.
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Liver and Muscle Glycogen Use During Exercise.
Lead sponsor: Northumbria University
Sponsor class: OTHER
Collaborators: name: University of Newcastle Upon-Tyne
name: Maastricht University
name: Sugar Nutrition, UK
First posted: 2014-04-10
Enrollment: 14
Sex: MALE
Minimum age (years): 18
Maximum age (years): 35
Standard ages: ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: CROSSOVER
Primary purpose: BASIC_SCIENCE

Brief summary: Carbohydrate is stored in the body as glycogen, which is mainly found in the liver and muscle. During endurance exercise, muscle glycogen is used as fuel for the working muscles and liver glycogen is broken down to provide glucose to maintain blood glucose (sugar) levels. Both liver and muscle glycogen are important for the ability to perform intense/prolonged endurance exercise. Therefore, nutritional strategies which can maximise the availability of glycogen in muscle and liver can benefit endurance exercise capacity.

The carbohydrates typically found in sports drinks are glucose and sometimes fructose. If glucose only is ingested during exercise, then the maximum rate at which can be absorbed from the intestine into the blood stream is \~1 g/min. However, if different sources of carbohydrate (fructose) are used, which are absorbed through a different pathway, absorption of carbohydrate can be up to \~1.8 g/min. With more carbohydrate available as a fuel, this translates into an improvement in performance.

Sucrose is a naturally occurring sugar that is made up of a single glucose and single fructose molecule. Therefore, theoretically, this can use the two different pathways of absorption and also maximise carbohydrate delivery. It is not yet known however, what impact this has on our liver and muscle glycogen stores during exercise. Therefore the aim of this study is to assess whether sucrose ingestion influences liver and muscle glycogen depletion during endurance exercise.


Eligibility criteria: Inclusion Criteria:

* Healthy
* Male
* 18 - 35 years of age
* Endurance trained cyclist/triathlete
* VO2 max ≥ 50 ml/kg/min

Exclusion Criteria:

* Use of medication
* Smoking
* Metabolic disorders

Primary outcomes:
measure: Change in liver glycogen concentration
timeFrame: 3 hours
Secondary outcomes:
measure: Plasma glucose concentration.
timeFrame: 3 hours
measure: Plasma lactate concentration
timeFrame: 3 hours
measure: Plasma non-esterified fatty acid concentration
timeFrame: 3 hours
measure: Indirect calorimetry
timeFrame: 3 hours
measure: Muscle glycogen concentration
timeFrame: 3 hours
measure: Change in intramyocellular lipid concentration
timeFrame: 3 hours
Other outcomes:
Locations:
city: Newcastle upon Tyne
country: United Kingdom
facility: Northumbria University
state: Tyne and Wear
Study officials:
affiliation: Maastricht University
name: Luc van Loon, PhD
role: PRINCIPAL_INVESTIGATOR
References:
citation: Gonzalez JT, Fuchs CJ, Smith FE, Thelwall PE, Taylor R, Stevenson EJ, Trenell MI, Cermak NM, van Loon LJ. Ingestion of glucose or sucrose prevents liver but not muscle glycogen depletion during prolonged endurance-type exercise in trained cyclists. Am J Physiol Endocrinol Metab. 2015 Dec 15;309(12):E1032-9. doi: 10.1152/ajpendo.00376.2015. Epub 2015 Oct 20.