Body Weight and Carb Metabolism

NCT05330481 | Completed

• 1 other identifier: 6632
• Study Type: observational
• Target: 20
• Locations: 1 country
• Sites: 1

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.

Conditions

Exercise Metabolism

Outcome Measures

Primary Outcomes (2)

• Peak exogenous carbohydrate oxidation rate (g/min)

  Peak exogenous carbohydrate oxidation rate (g/min)

  120 minute

• Total exogenous carbohydrate oxidation (g)

  Sum of exogenous carbohydrate oxidation in g

  minutes 30-120 of exercise

Secondary Outcomes (23)

• Total exogenous carbohydrate oxidation (g/kgFFM)

  minutes 30-120 of exercise i

• Whole-body carbohydrate oxidation rate (g)

  minutes 30-120 of exercise

• Whole-body carbohydrate oxidation rate (mg/kgFFM)

  Sum of minutes 30-120 of exercise

• Endogenous carbohydrate oxidation rate (g)

  minutes 30-120 of exercise

• Endogenous carbohydrate oxidation rate (mg/kgFFM)

  minutes 30-120 of exercise

Study Arms (2)

<70 kg body mass

Cyclists or triathletes with a body mass of less than 70 kg

Other: Moderate-intensity (relative) exercise with glucose ingestion

>70 kg body mass

Cyclists or triathletes with a body mass of less than 70 kg

Other: Moderate-intensity (relative) exercise with glucose ingestion; Other: Moderate-intensity (absolute) exercise with glucose ingestion

Interventions

Moderate-intensity (relative) exercise with glucose ingestion OTHER

120 minutes of cycling at 95% of lactate threshold ingesting 90 g/h of glucose

<70 kg body mass; >70 kg body mass

Moderate-intensity (absolute) exercise with glucose ingestion OTHER

120 minutes of cycling at a power matched to participant in the \<70 kg body mass group, ingesting 90 g/h of glucose

>70 kg body mass

Eligibility Criteria

• Age: 18 Years - 60 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)
• Sampling Method: Non-Probability Sample

Study Population

Trained cyclists or triathletes

You may qualify if:

• 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

You may not qualify if:

• 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

Sponsors & Collaborators

• University of Bath: lead
• University of Birmingham: collaborator

Study Sites (1)

Department for Health, University of Bath

Bath, BA2 7AY, United Kingdom

Location

Biospecimen

Plasma

MeSH Terms

Interventions

Exercise

Intervention Hierarchy (Ancestors)

Motor Activity; Movement; Musculoskeletal Physiological Phenomena; Musculoskeletal and Neural Physiological Phenomena

Study Design

• Study Type: observational
• Observational Model: CASE CONTROL
• Time Perspective: CROSS SECTIONAL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Reader (Associate Professor) in Human Physiology

Study Record Dates

• First Submitted: March 2, 2022
• First Posted: April 15, 2022
• Study Start: March 1, 2022
• Primary Completion: April 27, 2024
• Study Completion: July 27, 2024
• Last Updated: September 19, 2024

Record last verified: 2024-09

Locations

GB (1)