Energy Profile and Low Intensity Activity (PROFILE)

Energy Adaptations During Active Workstation Use: Strategy for Individualization of Active Desk Programs

The recent literature has highlighting the importance of the time of SB and the level of physical activity (PA) as predictors of metabolic cardio risks. Now, sedentary lifestyles are well recognized as one of the causes of mortality. As with physical activity, a dose-response relationship appears to exist: mortality would increase with time spent in sedentary behaviors. However, this relationship would not be linear: the more the daily sitting time increases, the more the consequences on mortality are important. It is now well demonstrated that time spent in sedentary adult behaviour finds primarily its origin in the work, characterized by prolonged and uninterrupted periods of sitting. Many strategies have been settled to break the prolonged sitting time. The most promising one seem to be the use of active workstations (standing, walking, cycling, stepping) because they reduce sedentary time at work and increase physical activity with positive effects on the global health. However inter variability in energy response have been identified during a sit to stand allocation with subject "savers" profile showing an increase in energy expenditure while others categorized as "non-savers" increased significantly their energy expenditure between sitting and standing position. As others active workstation strategies exist, this study aim to first, better characterize energy response to posture and activity allocation (15min sit-15min stand-15min sit-15min low intensity cycling), secondly to identify parameters that could explain different energy profile.

Subject will have an inclusion visit during a medical consultation where the eligibility criteria to participate to this study will be checked.

During a second experimental visit, subjects will have to take a calibrated breakfast. Three hours after the breakfast, body composition will be assessed and energy expenditure and substrates oxidation will be measured with an indirect calorimetry device during 15min in a sitting position fallowed by 15min in standing position , 15min in a sitting position and 15min of low intensity cycling with a cycling desk.

Then subjects will underwent physical capacity test :

• 6min step test
• Handgrip test
• lower limb strength test Finally, subjects will be equipped with accelerometer and inclinometer device they will need to wore during 7 days.

Inclusion Criteria:

• Healthy volunteer, male or female, between 18 and 61 years old
• Body mass index > 18,5 kg/m2 and ≤ 25 kg/m2
• Able to provide informed consent to research participation
• Registered in the French social security system

Exclusion Criteria:

• Subject using a sit-to-stand office desk or a swiss ball
• Contact jobs (face-to-face with people)
• Pregnant or breastfeeding women
• Medical or surgical history determined by principal investigator to be not compatible with the study
• Subject with cardiorespiratory and/or osteo-articular disorders limiting their ability to perform physical tests or the use of active offices
• Subject with type 1 or type 2 diabetes treated with insulin
• Subject with progressive cardiovascular or neoplastic disease.
• Subject with a major infection within 3 months of inclusion.
• Subject with known neuromuscular pathology: myopathy, myasthenia, rhabdomyolysis, paraplegia, hemiplegia
• Subject with chronic or acute inflammatory pathology 3 months prior to inclusion