Clinical trial NCT02568592: Exercise Substrate Utilisation and Endurance Performance Following Short-term Manipulation of Dietary Fat Intake
Official title: Exercise Substrate Utilisation and Endurance Performance Following Short-term Manipulation of Dietary Fat Intake in Women
Study type: INTERVENTIONAL
Overall status: UNKNOWN
Phase: NA
Conditions: Dietary Modification
Lead sponsor: University of Birmingham
Sponsor class: OTHER
Collaborators: name: GlaxoSmithKline
First posted: 2015-10-06
Enrollment: 16
Sex: FEMALE
Minimum age (years): 18
Maximum age (years): 45
Standard ages: ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: CROSSOVER
Primary purpose: BASIC_SCIENCE

Brief summary: The capacity to burn fat as fuel for exercise may have important implications for sporting performance, with dietary fat intake positively influencing this ability.

Endurance performance and the ability to burn fat will be measured in women runners following the consumption of 3 diets varying in the amount of fat and carbohydrate.

Detailed description: Dietary fat intake positively influences the ability to burn fat during exercise in women but not men, whereas carbohydrate intake negatively influences fat oxidation in both sexes. The independent nature of dietary fat intake as a predictor of the ability to burn fat in women suggests that in conditions of adequate carbohydrate intake providing additional fat may increase fat oxidation in women whereas it does not in men. It is of interest to explore if indeed women are responsive (i.e., increase in fat oxidation) to short-term increases in dietary fat intake induced by overfeeding (adequate carbohydrate) or if as appears to be the case in men reduced carbohydrate intake as typically employed in high-fat, low carbohydrate dietary studies is also a prerequisite for enhancing fat oxidation in women, and whether this translates into a difference in exercise endurance performance.

Eligibility criteria: Inclusion Criteria:

* BMI \>17.0 \< 25 kg/m2
* Good General Health
* Accustomed to vigorous physical activity
* Run \> 2 times per week
* V̇O2max \>50ml/kg/min
* Weight Stable \> last 6months
* Non Smoker
* Pre-menopausal, and either eumenorrheic and regularly menstruating, or using monophasic hormonal oral contraceptives for \> 3 months.

Exclusion Criteria:

* Currently taking part in another scientific/clinical study
* Taking any prescription drug / supplement thought to influence metabolism
* Following unusual dietary practices (such as intermittent fasting or low carbohydrate diets)
* Pregnant
* Breast Feeding

Primary outcomes:
measure: Rates of fat oxidation during exercise
timeFrame: 90 minutes of sub-maximal exercise
Secondary outcomes:
measure: 5km running performance
timeFrame: Immediately following measurement of Primary Outcome measure
measure: Change in plasma glucose concentration
timeFrame: 90 minutes sub-maximal exercise
measure: Change in Free Fatty Acid concentration
timeFrame: 90 minutes sub-maximal exercise
measure: Change in plasma glycerol concentration
timeFrame: 90 minutes sub-maximal exercise
Other outcomes:
Locations:
city: Birmingham
country: United Kingdom
facility: University of Birmingham
state: West Midlands
Study officials:
affiliation: University of Birmingham
name: Gareth A Wallis, PhD
role: PRINCIPAL_INVESTIGATOR
References: