Introduction
The phrase physical activity can mean many things to different people; many people get confused between exercise and physical activity thinking that both are the same thing. The American College of Sports Medicine describe physical activity as a bodily activity or movement that increase energy expenditure by the contraction of skeletal muscles. (ACSM 2012). This means that physical activity is anything that increases energy expenditure, for example walking up the stairs or hovering up. Physical activity is generally unplanned whereas exercise is structured and consists of repetitive bodily movements, for example going for a run.
To gain the large amounts of health benefits associated with being physically fit excessive exercise is not required. The National Health Service and the Department of Health both state that adults should be completing a minimum of 150 minutes of physical activity per week. The physical activity should be moderate to vigorous intensity. Alternately 75 minutes of vigorous intensity activity across the week such as running, football or swimming. All adults should also aim to improve muscle strength on at least two days a week and minimise sedentary activities.
There are many health benefits associated with physical activity, there are also implications on health of inactivity and large prolonged periods of sedentary behaviour. Sedentary behaviour is not the absence of physical activity as many believed it is periods of doing very little so that energy expenditure is very low, for example sitting or lying down. People can be sedentary when sitting at work or reading a book, this is due to the very low energy expenditure.
Guidelines
As of current there are no universally accepted guidelines for the limit on the amount of sedentary time. The Department of health produced a report in March 2010 showing how different countries