Obesity is increasing rapidly all over the world not only in adults but also among children. As a modifiable component of total energy expenditure (TEE) ,the amount of energy expended during physical activity plays an important role in preventing weight gain. Decreased physical activity, coupled with an over-consumption of calories, lead to the change of body composition by storing energy as fat.Although several studies have simultaneously examined body composition with energy expenditure the independent roles of body composition with activity energy expenditure (AEE) are less firmly established. It's suspected shrewdly that energy expenditure is partly influenced by the body composition. The aim of the study is to examine the relation of AEE with body composition in a population of school-age children.

Body composition (ie. FAT% and FFM) will be evaluated by means of bioelectrical impedance analysis (BIA) with Inbody 720 (Biospace, Seoul, South Korea). Anthropometric dimensions will be recorded for all participants according to standard procedures. Height will be recorded to the nearest 1.0mm by using a field stadiometer (Seca Corporation, Germany). FitMate metabolic system (Cosmed, Rome, Italy) will be used to estimate AEE. Subjects will be tested in a 10-minute submaximal exercise test using the FitMate systems while taking cycling test at 50 Watts on an electrically braked bicycle ergometer. Each subject will be connected to a calibrated respiratory gas analyzer, a portable metabolic analyzer designed for measurement of oxygen consumption during exercise via a face mask. Heart rate will be simultaneously measured with the use of a Cosmed wireless HR monitor to track the participant's heart rate level.

Inclusion Criteria:

• Children in Shanghai

Exclusion Criteria:

• cardiovascular disease
• asthma
• severe disease conditions such as cancer and renal failure
• taking steroids (corticosteroids) or antidepressants

Children in Shanghai