Exercise
Conditions
Brief summary
The aim of this study is to characterise exogenous carbohydrate oxidation rates during exercise, when ingesting glucose (polymers) only, compared to glucose-fructose mixtures, and glucose-fructose mixtures ingested in hydrogel form.
Interventions
DIETARY_SUPPLEMENTFructose-maltodextrin
Fructose plus maltodextrin in a ratio of 1:1.4, diluted in water to produce a 16% carbohydrate solution.
DIETARY_SUPPLEMENTFructose-maltodextrin hydrogel
Fructose plus maltodextrin in a ratio of 1:1.4, encapsulated in an alginate-pectin hydrogel diluted in water to produce a 16% carbohydrate solution.
DIETARY_SUPPLEMENTGlucose-maltodextrin
Glucose plus maltodextrin in a ratio of 1:1.4, diluted in water to produce a 16% carbohydrate solution.
Sponsors
University of Birmingham
University of Bath
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
BASIC_SCIENCE
Masking
DOUBLE (Subject, Investigator)
Eligibility
Sex/Gender
MALE
Age
18 Years to 50 Years
Healthy volunteers
Yes
Inclusion criteria
* Maximal oxygen consumption \> 50 ml.kg-1.min-1 * \> 1 year training in endurance running or triathlon * No current injury or injury within the last three months * No history of cardiac or metabolic disease such as coronary heart disease or diabetes * No current or history of gastrointestinal issues * Successful completion of the physical activity readiness questionnaire (PAR-Q)
Exclusion criteria
* Female * Untrained in endurance running * Current injury or injury within the past three months * History of cardiac or metabolic disease such as coronary heart disease or diabetes * History of or current gastrointestinal issues such as irritable bowel syndrome * Unable to replicate diet and training for 3 and 5 days respectively prior to each experimental visit.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Peak exogenous carbohydrate oxidation rate | 120 minutes | Peak exogenous carbohydrate oxidation rate during 120 min of treadmill running. Measured using isotope ratio mass spectrometry and reported in grams per minute |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Ratings of gastrointestinal discomfort | 120 minutes | Subjective ratings of gastrointestinal discomfort during 120 min of treadmill running. Measured using a 9-item questionnaire on a scale of 1 to 7, where 1 = No discomfort at all and 7 = very severe discomfort. Items: Stomach; Heartburn; Acid reflux; Nausea; Rumbling; Bloated; Burping; Passing gas; Bowel movement. |
| Total fat oxidation | 120 minutes | Total fat oxidation during 120 min of treadmill running. Measured using indirect calorimetry and reported in grams. |
| Plasma insulin concentrations | 120 minutes | Plasma insulin concentrations during 120 min of treadmill running. Measured using enzyme-linked immunosorbent assay and reported in pmol/L. |
| Plasma glucose concentrations | 120 minutes | Plasma lactate concentrations during 120 min of treadmill running. Measured using colourimetric assay and reported in mmol/L. |
| Plasma lactate concentrations | 120 minutes | Plasma lactate concentrations during 120 min of treadmill running. Measured using colourimetric assay and reported in mmol/L. |
| Total carbohydrate oxidation | 120 minutes | Total carbohydrate oxidation during 120 min of treadmill running. Measured using indirect calorimetry and reported in grams. |
| Ratings of perceived exertion | 120 minutes | Subjective ratings of perceived exertion using the Borg scale (1982) during 120 min of treadmill running. Measured on a scale of 6 to 20, where 6 = no exertion at all, and 20 = maximal exertion. |
| Heart rate | 120 minutes | Heart rate during treadmill running measured by telemetry and reported in beats per minute. |
| Rate of oxygen consumption | 120 minutes | Rate of oxygen consumption during 120 min of treadmill running. Measured using indirect calorimetry and reported in litres per minute. |
| Rate of carbon dioxide production | 120 minutes | Rate of carbon dioxide production during 120 min of treadmill running. Measured using indirect calorimetry and reported in litres per minute. |
| Plasma non-esterified fatty acid concentrations | 120 minutes | Plasma insulin concentrations during 120 min of treadmill running. Measured using colourimetric assay and reported in umol/L. |
Countries
United Kingdom
Outcome results
None listed