To assess exogenous and endogenous carbohydrate oxidation rates during prolonged (3 h) endurance-type exercise (Part A) or muscle glycogen repletion following exercise (Part B) while ingesting glucose-only, or glucose plus fructose or glucose plus…
ID
Source
Brief title
Condition
- Other condition
Synonym
Health condition
carbohydrate oxidation and glycogen repletion
Research involving
Sponsors and support
Intervention
Outcome measures
Primary outcome
Part A: The main study parameter is exogenous and endogenous carbohydrate
oxidation.
Part B: The main study parameter is muscle glycogen repletion.
Secondary outcome
Secondary parameters include substrate utilization (VO2, VCO2 and RER) (Part A
only) and free fatty acids (Part B only) in addition to plasma lactate, insulin
and glucose.
Background summary
Carbohydrates are an integral component of sports nutrition. Providing
carbohydrate (CHO) during exercise delays the onset of fatigue and improves
exercise performance by maintaining high rates of CHO oxidation. Traditionally,
glucose, or glucose polymers have been the preferential CHO source found in
sports drinks. However, during the intestinal absorption of large amounts of
glucose (>1.2 g/min), sodium-dependent
Study objective
To assess exogenous and endogenous carbohydrate oxidation rates during
prolonged (3 h) endurance-type exercise (Part A) or muscle glycogen repletion
following exercise (Part B) while ingesting glucose-only, or glucose plus
fructose or glucose plus sucrose (1.8 g/min).
Study design
Double-blind, cross-over, randomized study.
Intervention
Ingesting 1.8 g/min of glucose or glucose-fructose (1.2 g/min + 0.6 g/min
respectively) or glucose-sucrose (0.6 g/min + 1.2 g/min respectively) during 3
h of endurance-type cycling exercise (Part A) or during 6 h of post-exercise
recovery (Part B).
Study burden and risks
Part A and B are each comprised of 4 laboratory visits, comprised of 1
screening visit and 3 experimental visits. Subjects will have to record their
diet and activity patterns for 48 h prior to 3 visits and duplicate these
patterns during visits 3 and 4. The potential risks and discomforts inherent to
the exercise testing procedure during each visit are minimal and are similar to
those associated with any form of strenuous physical activity including
fatigue, fainting, abnormal blood pressure etc. Subjects will provide either 13
blood samples (Part A) or 16 samples (Part B) during visits 2-4. Insertion of
the catheters in a vein is comparable to a normal blood draw and the only risk
is a small local hematoma. This is also true for muscle biopsies (Part B).
Three muscle biopsies (Part B) will be taken through a small (5 mm) incision,
following local anesthetics of the skin and muscle fascia, and will heal
completely during visits 2-4. Muscle biopsies will only be obtained by an
experienced physician.
Maastricht University Medical Centre 616
Maastricht 6200 MD
NL
Maastricht University Medical Centre 616
Maastricht 6200 MD
NL
Listed location countries
Age
Inclusion criteria
- Healthy
- Male
- 18 - 40 years of age
- Cyclist or triathlete
- VO2 max * 50 ml/kg/min
- BMI <25 kg/m2
Exclusion criteria
- Use of medication
- Smoking
Design
Recruitment
Followed up by the following (possibly more current) registration
No registrations found.
Other (possibly less up-to-date) registrations in this register
No registrations found.
In other registers
| Register | ID |
|---|---|
| ClinicalTrials.gov | NCT01709617 |
| CCMO | NL41813.068.12 |