A sedentary lifestyle over several years is associated with increased risk for type 2 diabetes, cardiovascular disease, and premature mortality. What is much less appreciated is the high cost of physical inactivity even in the short term. Booth et al. have been drawing attention for years to the societal and individual burden of inactivity-related chronic diseases. They remind us that while exercise is a treatment to prevent many chronic diseases, it is the lack of regular exercise or physical inactivity that is one of the actual causes of many of these diseases’ (481).
Convincing proof that physical inactivity causes primary deterioration of function is provided from extensive historical and scientific evidence. Thus, physical activity can prevent physical inactivity-induced chronic diseases (left panel of Fig 1). In contrast (right panel of Fig 1), physical activity can treat against lung cancer-induced dyspnea, a common side effect 1 to 6 years after lung cancer resection (179) (Right panel Fig. 1). Thus, in the left panel physical activity addresses the cause of the disease, while in the right panel physical activity only acts as a treatment against a disease in which it cannot prevent. We will focus on the disease processes of the left panel in this article.”