None listed
Conditions
Brief summary
The purpose of this study is to evaluate hunger, energy intake, antropyloroduodenal motility, and plasma concentrations of the gut hormones, ghrelin, cholecystokinin (CCK), peptide YY3-36 (PYY3-36), and glucagon-like peptide-1 (GLP-1), in response to exercise of two intensities, 35% and 70% of peak oxygen consumption (VO2), and a no-exercise control condition, in healthy, lean young men. Each subject will be studied on three occasions. Each visit will be either sedentary or involve exercise at one of two intensities (35 and 70% VO2max) for 60 minutes, with the three interventions administered in a counter-balanced order. On each occasion antropyloroduodenal motility, plasma CCK, ghrelin, GLP-1, and PYY3-36 concentrations, appetite perceptions, energy intake and energy expenditure will be measured. Peak aerobic capacity of each subject will be determined within a week before the start of the study using a screening treadmill test. During this screening test, as well as at intervals during the study, subjects will breathe through a mouthpiece equipped with a two-way valve. VO2max will be measured from expired gases that are continuously sampled by a metabolic cart.
Interventions
Sixteen (BMI 19-25 kg/m2) healthy subjects, aged between 18 - 35 years, will be recruited. All subjects will be required to be weight-stable at study entry, as determined by their self-reported weight in the preceding 3 months, and will be required to maintain their normal physical activity over the course of the study.
Each subject will be studied on three occasions, separated by at least 3 (and up to 7) days. Each visit will be either sedentary or involve exercise on a treadmill at one of tw
Sixteen (BMI 19-25 kg/m2) healthy subjects, aged between 18 - 35 years, will be recruited. All subjects will be required to be weight-stable at study entry, as determined by their self-reported weight in the preceding 3 months, and will be required to maintain their normal physical activity over the course of the study. Each subject will be studied on three occasions, separated by at least 3 (and up to 7) days. Each visit will be either sedentary or involve exercise on a treadmill at one of two intensities (35 and 70% VO2max) for 60 minutes, with the three interventions administered in a counter-balanced order, by administering the various procedures in different sequences. On each occasion antropyloroduodenal motility, plasma CCK, ghrelin, GLP-1, and PYY concentrations, appetite perceptions, energy intake and energy expenditure will be measured. Peak aerobic capacity of each subject will be determined within a week before the start of the study using a screening treadmill test (GXT), which will be supervised by a medical doctor in the Department of Medicine. This test involves collection of ventilatory and respirometric measurements from the subject during progressive increases in speed (0.8 km/h/2 min) while walking/running on a level treadmill. During the GXT, subjects will be monitored with a Polar a 12-lead electrocardiogram will be performed, and blood pressure will also be monitored. The subjects will also wear the SenseWear bands to provide a direct comparison with the VO2 max test.. During this screening test, as well as at intervals during the study, subjects will breathe through a mouthpiece equipped with a two-way valve. This protocol is well established and commonly used in exercise studies (62). Peak oxygen consumption (VO2peak) will be measured from expired gases that are continuously sampled from a mixing-chamber and analyzed for gas flow and for oxygen (O2) and carbon dioxide (CO2) concentrations by a metabolic cart (VO2000, Medgraphics, St. Paul, MN, USA). Heart rate will be monitored with a Polar® heart rate strap and watch.
Sponsors
Christine Feinle-Bisset
Study design
Allocation
Randomised controlled trial
Intervention model
Crossover
Primary purpose
Treatment
Masking
Blinded (masking used) (Subject, Caregiver, Investigator, Outcomes Assessor)
Eligibility
Sex/Gender
Male
Age
19 Years to 35 Years
Healthy volunteers
Yes
Inclusion criteria
Sixteen (BMI 19-25 kg/m2) healthy subjects, aged between 18 - 35 years, will be recruited. All subjects will be required to be weight-stable (i.e. < 5 % fluctuation in their body weight) at study entry, as determined by their self-reported weight in the preceding 3 months, and will be required to maintain their normal physical activity over the course of the study.
Exclusion criteria
Each subject will be questioned prior to the study to exclude: - significant GI symptoms, disease or surgery - use of prescribed or non-prescribed medications (including vitamins and herbal supplements) which may affect energy metabolism, GI function, body weight or appetite (e.g. domperidone and cisapride, anticholinergic drugs (eg atropine), metoclopramide, erythromycin, hyoscine, orlistat, green tea extracts, Astragalus, St Johns Wort etc.) - lactose intolerance or other food allergy(s) - current gallbladder or pancreatic disease - diabetes mellitus - epilepsy - cardiovascular or respiratory diseases - any other illnesses as assessed by the investigator (including chronic illnesses not explicitly listed above) - high performance athletes - current intake of > 2 standard drinks on > 5 days per week - current smokers of cigarettes/cigars/marijuana - current intake of any illicit substance - restrained eaters (score > 12 on the three factor eating questionnaire) - experience of claustrophobia in confined spaces - inability to tolerate nasoduodenal tube - inability to comprehend study protocol
Outcome results
None listed