Poor lifestyle choices associated with advancing age are characterized by physical inactivity and increased fat mass. It is estimated that physical inactivity is associated with around 9 % of premature deaths worldwide (5.3 million) from noncommunicable diseases . The burden of chronic disease associated with physical inactivity ranges from 6 % for coronary heart disease to 10 % for breast and colon cancer . The aetiology of many of these diseases is associated with immunese- nescence and inflammation . This chapter will discuss studies which have assessed the effects of physical activity, structured exercise and energy balance on immune function and inflammation in the aged, and what still needs to be done to better understand the benefits of exercise for immunity. In light of the majority of research on exercise immunology being conducted in younger individuals or animal models, these will be referred to in the absence of data pertaining to older humans.
Maintaining regular habitual physical activity levels throughout life is associated with a number of health benefits including, reduced risk of cardiovascular disease (CVD), diabetes and stroke; as well as reduced physical disability and mortality . However, after the age of 45 years there is a progressive and sharp decline in both time and intensity of physical activity which is attributed to a lack of time, motivation and knowledge of the health benefits . Reduced physical activity is associated with a positive energy balance leading to increased adiposity and subsequently systemic inflammation . The link between immunesenescence and inflammation is clear with the two having major negative effects on health . In the following sections we will describe the effects of different measures of exercise on immune function and the role exercise has in modifying immunesenescence and inflammation.