Exercise and balanced nutrition are important components of a healthy lifestyle. Exercise habits are classified along a continuum comprising individuals with different motives for exercise. At one end of this continuum are individuals who undertake “incidental” physical activity as part of their vocation and/or domestic duties. In the middle of the continuum are individuals who exercise recreationally to maintain good health. At the other end of the continuum are athletes who train intensely to achieve competitive success. Interest in the relationship between exercise, diet, and immune function has increased in the past 2 decades for several reasons. Exercise is often prescribed for individuals with chronic diseases or [Page 1134]individuals undergoing treatment that affects the immune system. Examples of such individuals include patients with cancer or ...