High altitude simulation and weight management

Recruiting

Conditions: overweight (25 < BMI < 30)
bulky
Corpulence

Registration Number: NL-OMON33006

Lead Sponsor: HAN University (Hogeschool van Arnhem en Nijmegen)

Brief Summary: Not available

Detailed Description: Not available

Recruitment & Eligibility

Status: Recruiting

Sex: Not specified

Target Recruitment: 20

Inclusion Criteria

Women
Self reported healthy
20 - 40 years
25 < BMI < 30
Non - smoking
Activity level < Dutch 'Fitnorm'

Exclusion Criteria

Extreme sensitive to hypoxia (oxygen saturation < 90 % at pO2 = 129 mm Hg)
• Anaemia (Hb < 7.5 mmol/L, Hc < 41%)
• Diabetes (fasting plasma glucose > 5.8 mmol/L and/or glucosuria)
• Following weight-reduction programme or medically prescribed diet
• Weight change > 2 kg during the last 2 months
• Medication that may influence energy metabolism, weight or food intake
• Gastrointestinal disorders (blood in stool, constipation and diarrhoea)
• History of medical or surgical events that may affect the study outcome
• Blood donation in the last month before the study or during the study
• Abnormal ECG or impaired lung function

Study & Design

Study Type: Interventional

Study Design: Not specified

Primary Outcome Measures

Name	Time	Method
<p>As parameter of energy expenditure whole body oxygen consumption is measured<br /><br>via indirect calorimetry (ventilated hood).<br /><br>A work load of 85 Watt on a bike ergometer (the maximum in this study) requires<br /><br>at sea level an energy expenditure of 20.4 kJ/min.<br /><br>We expect that the same work load under high altitude simulation requires an<br /><br>energy expenditure of 28.6 kJ/min, an increase of about 40%.<br /><br>In other words a work load of 85 Watt under high altitude simulation is<br /><br>associated with an energy expenditure for which under sea level conditions a<br /><br>work load of 115 Watt has to be applied. </p><br>

Secondary Outcome Measures

Name	Time	Method
<p>The CO2 production of the subjects is also measured via the ventilated hood<br /><br>system. In combination with the oxygen consumption the Respiratory Quotient (RQ<br /><br>= CO2/O2) can be determined. Changes in RQ are indicative for for changes in<br /><br>substrate use. During the exercise protocols at regular time intervals 10 ul<br /><br>blood samples are taken from the middle finger to detect changes in glucose and<br /><br>lactate levels in peripheral blood. During the exercise protocols the lactate<br /><br>level should be higher compared to rest and may increase slightly.<br /><br>The physiological condition of the subjects is continuously monitored via<br /><br>oxygen saturation of the blood (SpO2), the heart rate (HR) and a RPE (Rate of<br /><br>Perceived Exertion) questionaire. The protcol is stopped when the subject wants<br /><br>to do so and when the pre-determined endpoint values are reached; SpO2 < 90% en<br /><br>HR > 80% HRmax.</p><br>