Carbohydrate Intake and Gut Hormone Release During Exercise
It is well known that following a single session of moderate-to-high intensity exercise individuals experience a temporary suppression of hunger and a delay in the commencement of eating. This effect is believed to be due to changes in blood concentrations of specific hormones released from the gut that influence appetite.
Individuals undertaking physical activity often consume foods immediately before exercise in order to improve their performance. However, it is currently unknown whether this eating practice influences the gut hormone response to exercise as well as how hungry an individual feels post-exercise.
Therefore, the aim of this study is to investigate the effect of consuming a sugary (carbohydrate) drink immediately before starting an exercise session on the concentration of these gut hormones as well as the amount of food eaten in the hours following exercise completion.
Study Overview
Status
Status
Conditions
Conditions
Intervention / Treatment
Intervention / Treatment
Detailed Description
It is well established that following an acute bout of moderate-to-high intensity exercise individuals experience a transient suppression of hunger and a delay in the commencement of eating - a phenomenon referred to as exercise-induced anorexia. Acute exercise modulates the concentrations of gut hormones known to influence satiety, including the anorexigenic hormones glucagon-like peptide 1 (GLP-1) and peptide tyrosine tyrosine (PYY), as well as the acylated form of the orexigenic hormone ghrelin. These alterations in gut hormone concentrations have consequently been hypothesised to play a key role in exercise-induced anorexia.
Despite suppressing hunger and delaying eating, acute exercise does not appear to alter short-term energy intake in the immediate hours following exercise completion. The absence of a compensatory response therefore creates an energy deficit capable of inducing weight loss. Strategies that augment the gut hormone response to acute exercise may thus increase the potency of exercise as a weight-loss tool.
Research investigating the effect of exercise on appetite has frequently utilised participants in a fasting state. Undertaking exercise in this physiological condition contradicts current practices, as athletes often consume a carbohydrate source immediately prior to exercise in an attempt to maximise performance. It is currently unknown as to whether the consumption of carbohydrate during this period may further enhance the gut hormone response to exercise, and thus research into a potential additive effect is warranted.
High-intensity exercise increases sympathetic nervous system activity and catecholamine release. Catecholamine concentrations are negatively correlated with acylated ghrelin concentrations and may directly stimulate GLP-1 and PYY release via activation of β-receptors located on L-cells. The decrease in gastric emptying rate that is observed during high-intensity exercise is also attributed to this increase in sympathetic activity. Consequently, an increase in sympathetic nervous system activity has been postulated as a key mechanism underlying exercise-induced changes in gut hormone concentrations. However, to our knowledge, no study has directly measured the relationship between sympathetic nervous system activity and anorexigenic gut hormone release during exercise.
Therefore, the aim of this study is to examine any potential additive effects of carbohydrate ingestion immediately prior to exercise on gut hormone release and post-exercise appetite suppression. Furthermore, this study will look to investigate the mechanisms underlying changes in gut hormone concentrations experienced during exercise.
Study Type
Study Type
Enrollment (Actual)
Enrollment
Phase
Phase
- Not Applicable
Contacts and Locations
Study Locations
-
-
-
London, United Kingdom, W12 0HS
- Imperial Clinical Research Facility
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-
Participation Criteria
Eligibility Criteria
Eligibility Criteria
Ages Eligible for Study
Accepts Healthy Volunteers
Description
Inclusion Criteria:
- Male
- Age between 18-40 years (inclusive)
- Body mass index (BMI) of 18-30 kg/m2
- Willingness and ability to give written informed consent and willingness and ability to understand, to participate and to comply with the study requirements
Exclusion Criteria:
- Abnormal ECG
- Screening blood results outside of normal reference values
- Current smokers
- Current or history of substance abuse and/or excess alcohol intake
- Diabetes
- Cardiovascular disease
- Cancer
- Gastrointestinal disease e.g. inflammatory bowel disease or irritable bowel syndrome
- Kidney disease
- Liver disease
- Pancreatitis
- Started new medication within the last 3 months likely to interfere with energy metabolism, appetite regulation and hormonal balance, including: anti-inflammatory drugs or steroids, antibiotics, androgens, phenytoin, erythromycin or thyroid hormones.
- Participation in a research study in the 12 week period prior to entering this study.
- Any blood donation within the 12 week period prior to entering this study
Study Plan
How is the study designed?
Design Details
- Primary Purpose: Basic Science
- Allocation: Randomized
- Interventional Model: Crossover Assignment
- Masking: Double
Number of Arms
Arms and Interventions
Participant Group / ArmParticipant Group / Arm |
Intervention / TreatmentIntervention / Treatment |
|---|---|
|
Placebo Comparator: No Carbohydrate Drink + Rest
Participants will consume the no carbohydrate drink (300ml water) followed by a rest session
|
30 minutes laying on a bed
A drink containing 300ml of water
|
|
Active Comparator: No Carbohydrate Drink + Exercise
Participants will consume the no carbohydrate drink (300ml water) followed by an exercise session (75% VO2 max on a cycle ergometer)
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A drink containing 300ml of water
30 minutes on a cycle ergometer working at 75% VO2 max
|
|
Active Comparator: Carbohydrate Drink + Rest
Participants will consume the carbohydrate drink (300ml water + 75g maltodextrin) followed by a rest session
|
30 minutes laying on a bed
A drink containing 300ml of water and 75g of maltodextrin
|
|
Experimental: Carbohydrate Drink + Exercise
Participants will consume the carbohydrate drink (300ml water + 75g maltodextrin) followed by an exercise session (75% VO2 max on a cycle ergometer)
|
30 minutes on a cycle ergometer working at 75% VO2 max
A drink containing 300ml of water and 75g of maltodextrin
|
What is the study measuring?
Primary Outcome Measures
Primary Outcome Measures
Outcome Measure |
Measure Description |
Time Frame |
|---|---|---|
|
Changes in GLP-1 concentration
Time Frame: During the study visit, 165 minutes
|
Changes in GLP-1 concentration between exercise and resting conditions, and between carbohydrate and control conditions
|
During the study visit, 165 minutes
|
|
Changes in PYY concentration
Time Frame: During the study visit, 165 minutes
|
Changes in PYY concentration between exercise and resting conditions, and between carbohydrate and control conditions
|
During the study visit, 165 minutes
|
|
Changes in acylated ghrelin concentration
Time Frame: During the study visit, 165 minutes
|
Changes in acylated ghrelin concentration between exercise and resting conditions, and between carbohydrate and control conditions
|
During the study visit, 165 minutes
|
Secondary Outcome Measures
Secondary Outcome Measures
Outcome Measure |
Measure Description |
Time Frame |
|---|---|---|
|
Changes in energy intake
Time Frame: During the study visit, 165 minutes
|
Differences in energy intake at an ad libitum meal between exercise and resting conditions, and between carbohydrate and control conditions
|
During the study visit, 165 minutes
|
|
Changes in Energy expenditure
Time Frame: During the study visit, 165 minutes
|
Differences in energy expenditure between exercise and resting conditions, and between carbohydrate and control conditions.
|
During the study visit, 165 minutes
|
|
Changes in energy balance
Time Frame: During the study visit, 165 minutes
|
Differences in energy balance between exercise and resting conditions, and between carbohydrate and control conditions.
|
During the study visit, 165 minutes
|
|
Glucose homeostasis
Time Frame: During the study visit, 165 minutes
|
Changes in glucose homeostasis between exercise and resting conditions, and between carbohydrate and control conditions.
|
During the study visit, 165 minutes
|
|
Changes in subjective nausea
Time Frame: During the study visit, 165 minutes
|
Changes in subjective feelings of nausea as measured by visual analogue scales between exercise and resting conditions, and between carbohydrate and control conditions.
Visual analogue scales will range from 0 mm to 100 mm with a higher score indicating a higher degree of nausea.
|
During the study visit, 165 minutes
|
|
Changes in subjective appetite
Time Frame: During the study visit, 165 minutes
|
Changes in subjective feelings of appetite as measured by visual analogue scales between exercise and resting conditions, and between carbohydrate and control conditions.
Visual analogue scales will range from 0 mm to 100 mm with a higher score indicating a higher degree of fullness.
|
During the study visit, 165 minutes
|
Collaborators and Investigators
Sponsor
Sponsor
Investigators
Investigators
- Principal Investigator: Edward Chambers, PhD, Imperial College London
Publications and helpful links
Study record dates
Study Major Dates
Study Start (Actual)
Study Start
Primary Completion (Actual)
Primary Completion
Study Completion (Actual)
Study Completion
Study Registration Dates
First Submitted
First Submitted
First Submitted That Met QC Criteria
First Submitted That Met QC Criteria
First Posted (Actual)
First Posted
Study Record Updates
Last Update Posted (Actual)
Last Update Posted
Last Update Submitted That Met QC Criteria
Last Update Submitted That Met QC Criteria
Last Verified
Last Verified
More Information
Terms related to this study
Other Study ID Numbers
Other Study ID Numbers
- 18HH4889
Plan for Individual participant data (IPD)
Plan to Share Individual Participant Data (IPD)?
IPD Plan Description
Drug and device information, study documents
Studies a U.S. FDA-regulated drug product
Studies a U.S. FDA-regulated device product
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