Clinical trial NCT05330481: Body Weight and Carb Metabolism
Official title: Exploring the Role of Body Mass in Exogenous Carbohydrate Oxidation Rates During Exercise
Study type: OBSERVATIONAL
Overall status: COMPLETED
Conditions: Exercise Metabolism
Lead sponsor: University of Bath
Sponsor class: OTHER
Collaborators: name: University of Birmingham
First posted: 2022-04-15
Enrollment: 20
Sex: ALL
Minimum age (years): 18
Maximum age (years): 60
Standard ages: ADULT
Accepts healthy volunteers: yes
Observational model: CASE_CONTROL
Time perspective: CROSS_SECTIONAL
Sampling method: NON_PROBABILITY_SAMPLE
Study population: Trained cyclists or triathletes

Brief summary: Whilst theoretically, body size should influence the capacity for intestinal carbohydrate absorption and thus exogenous oxidation rates during exercise, there is currently little empirical evidence to support this hypothesis. Accordingly, current nutrition guidelines for carbohydrate intake during exercise do not take body mass into account. Therefore, there is a need to establish whether body mass is related to exogenous carbohydrate oxidation rates during exercise. If such a relationship is established, this would lay the foundation to revise the current sports nutrition guidelines regarding carbohydrate intake during exercise.

The aims of this study are, therefore, to: 1) establish whether larger individuals display higher rates of exogenous carbohydrate oxidation than smaller individuals; and 2) establish if such a difference can be explained by the higher absolute exercise intensity, and thus the energy demand of exercise. It is hypothesised that larger individuals will demonstrate higher exogenous carbohydrate oxidation rates than smaller individuals, and that this difference will be partly (but not completely) diminished when the absolute intensity of exercise is matched.


Eligibility criteria: Inclusion Criteria:

* Able to cycle continuously for 2 hours at a moderate intensity
* VO2max of between 40-75 mL/kg/min
* Fat-mass index (determined by dual energy x-ray absorptiometry) \< 5.5 kg·m-2

Exclusion Criteria:

* Diagnosed disorders of the gastrointestinal tract (e.g. crohn's, colitis etc.)
* People following a low-carbohydrate, high-fat diet
* Pregnant or lactating
* Diagnosed cardiovascular disease
* Possible symptoms of cardiovascular disease
* Diagnosis of diabetes of any type
* Hypercholesterolaemia (total cholesterol ≥ 6.2 mmol/L
* Hypertension (systolic blood pressure ≥140 mmHg or diastolic blood pressure ≥90 mmHg)
* Current smoker
* Family history of coronary artery disease (first-degree relative \<60 years)
* Prevalence of vascular disease
* Autonomic neuropathy
* Kidney disease
* Diagnosed pulmonary disease (e.g. chronic obstructive pulmonary disease, asthma, interstitial lung disease or cystic fibrosis)
* Blood borne disease or infection
* Osteoporosis
* Osteoarthritis
* Blood clotting disorders
* Food intolerances/allergies (these may not specifically exclude you- please talk to the investigator)
* Sensitivity or allergy to anaesthetic

Primary outcomes:
measure: Peak exogenous carbohydrate oxidation rate (g/min)
timeFrame: 120 minute
measure: Total exogenous carbohydrate oxidation (g)
timeFrame: minutes 30-120 of exercise
Secondary outcomes:
measure: Total exogenous carbohydrate oxidation (g/kgFFM)
timeFrame: minutes 30-120 of exercise i
measure: Whole-body carbohydrate oxidation rate (g)
timeFrame: minutes 30-120 of exercise
measure: Whole-body carbohydrate oxidation rate (mg/kgFFM)
timeFrame: Sum of minutes 30-120 of exercise
measure: Endogenous carbohydrate oxidation rate (g)
timeFrame: minutes 30-120 of exercise
measure: Endogenous carbohydrate oxidation rate (mg/kgFFM)
timeFrame: minutes 30-120 of exercise
measure: Whole-body fat oxidation rate (g)
timeFrame: minutes 30-120 of exercise
measure: Whole-body fat oxidation rate (mg/kgFFM)
timeFrame: minutes 30-120 of exercise
measure: Plasma lactate concentrations (mmol/L)
timeFrame: minutes 0-120 of exercise
measure: Plasma glucose concentrations (mmol/L)
timeFrame: minutes 0-120 of exercise
measure: Plasma non-esterified fatty acid concentrations (mmol/L)
timeFrame: minutes 0-120 of exercise
measure: Plasma insulin concentrations (pmol/L)
timeFrame: minutes 0-120 of exercise
measure: Dietary carbohydrate intake (grams/day)
timeFrame: 72-hour food diary in g/d
measure: Dietary sugar intake (grams/day)
timeFrame: 72-hour food diary
measure: Dietary fibre intake (grams/day)
timeFrame: 72-hour food diary
measure: Dietary fat intake (grams/day)
timeFrame: 72-hour food diary
measure: Dietary protein intake (grams/day)
timeFrame: 72-hour food diary
measure: Dietary energy intake (kiloJoules/day)
timeFrame: 72-hour food diary
measure: Dietary energy intake (kilojoules/kilogram/day)
timeFrame: 72-hour food diary
measure: Dietary carbohydrate intake (grams/kilogram/day)
timeFrame: 72-hour food diary
measure: Dietary sugar intake (grams/kilogram/day)
timeFrame: 72-hour food diary
measure: Dietary fibre intake (grams/kilogram/day)
timeFrame: 72-hour food diary
measure: Dietary fat intake (grams/kilogram/day)
timeFrame: 72-hour food diary
measure: Dietary protein intake (grams/kilogram/day)
timeFrame: 72-hour food diary
Other outcomes:
Locations:
city: Bath
country: United Kingdom
facility: Department for Health, University of Bath
Study officials:
References: