Physical activity is defined as any physical movement made by skeletal muscles which involves an energetic investment which requires an energy output. Physical activity covers all activities, at any level, carried out during any period of the day or night, inclusive of sleep. It also includes incidental activity and exercise integrated into normal daily activity. It is measured using a variety of criteria, including the amount of oxygen used, heart rate, muscular power and endurance, and body weight. These are thought to be influenced by genetic, psychological and physiological factors.
The health benefits associated with regular physical activity are well documented and numerous. Whilst sedentary lifestyles and poor eating habits are commonly blamed for leading to obesity and other health problems, research continually reveals that the correlation between diet and physical activity is often insignificant, if it exists at all. Furthermore, obesity and poor physical activity levels are commonly found in people of young adult age groups and in physically disabled individuals. The higher level of activity required to promote good health in adults can often be considered a form of stress relief and therefore a worthy addendum to any healthy lifestyle program. Adults who are highly active are less likely to develop chronic conditions such as diabetes and heart disease, as well as suffering from debilitating arthritis. This is especially the case in elderly adults who experience much higher activity levels than younger people.
Activity levels of different groups were compared in a recent study of 2,811 adults aged 55 years and above. Overall, higher activity levels were found among the overweight/obese group but there was a significant difference in physical activity intensity levels between groups. These results are important as they show that physical activity levels may be an important factor in the onset of chronic conditions. However, more research is needed to understand whether there are links between obesity and the onset of some age-related diseases and how these links can be prevented.