Sedentary behaviour is any waking behaviour, in a seated or reclined position, with a low energy expenditure. Sedentary behaviour is strongly related to all-cause mortality and premature death, and is an independent risk factor for numerous health conditions, e.g. type II diabetes, obesity, cardiovascular disease, and mental ill-health. Two previous studies have highlighted that when sedentary, adults with learning disabilities have a higher energy expenditure and exhibit more non-activity related movements, e.g. fidgeting, in comparison to the general population. This difference in energy expenditure could important implications for research, such as the measurement of sedentary behaviour and physical activity, which is often based on energy expenditure levels derived in the general population.

This study aimed to:

1. measure energy expenditure during sedentary behaviours in adults with learning disabilities; and

2. calibrate accelerometers for the measurement of sedentary behaviour and physical activity in adults with learning disabilities.

Participants in this study took part in various sedentary behaviours (such as sitting and lying down) and physical activities (treadmill walking). During these activities, movement was measured using ActiGraph and ActivPAL accelerometers, and energy expenditure was objectively measured using breath-by-breath indirect calorimetry.

Energy expenditure increased from sedentary postures to fast walking, and people with lower energy expenditure at rest tended to remain lower during walking. Higher BMI was linked to lower energy expenditure; age and level of learning disabilities were not associated. The analysis for aim 2 is still ongoing.

This work was led by the University of Glasgow in collaboration with Glasgow Caledonian University. The project was funded by The Baily Thomas Charitable Fund.