To investigate associations between sedentary and active behaviour with bone health and functional ability, and to associate mechanical loading at the lumbar spine and hip in sedentary and active individuals with bone mineral density.

Significant proportions of adults engage in sedentary behaviour for prolonged periods of time which is generally regarded as having deleterious effects on health. However, far less is known about its specific effects on bone health. Exercise has been proposed as a method of improving bone health, as impact forces generated as the foot contacts the ground during physical activity have the potential to aid bone maintenance and development.

The properties of bone are regulated through the amount mechanical loading, frequency of loading and duration of loading endured, which can create an osteogenic effect. These variables can be quantified via accelerometry which records the magnitude, rate and duration of accelerations experienced at the site on the body where the accelerometer is worn. Although there is a vast amount of literature where accelerometers have been used to monitor physical activity, there is a lack of studies that use accelerometers to determine the most effective exercise for bone, especially in relation to the lumbar spine. Exploring the bone health and loading characteristics of sedentary and low and highly active non-sedentary individuals will provide evidence upon which to base future interventions that are likely to be of benefit for bone health in sedentary populations.

Inclusion Criteria:

Male or female aged 30 - 60 years Individuals who are sedentary and do not participate in physical activities Individuals who participate in some physical activities Individuals who are highly active Must be free from injury or illness that will affects following typical weekly routines.

Exclusion Criteria:

Any medical condition that affects bone health, e.g. osteoporosis. Currently takes medication that affects bone health, e.g. long term steroid use.

Inability to participate in typical daily activity, e.g. severe arthritis, injury. Women who are post menopause Women who are on hormone replacement therapy Unable to participate in DXA scan, e.g. due to recent exposure to radiation, pregnancy status.

Sedentary and non-sedentary populations.