In her Research Highlight (King, A. Public health: Health risks of physical inactivity similar to smoking. Nat. Rev. Cardiol. 9, 492 [2012]),1 Alexandra King refers to the impact of health risks related to physical inactivity. Lack of physical exercise accounts for approximately 1 in 10 deaths annually, and up to 10% of noncontagious diseases such as type 2 diabetes mellitus, coronary heart disease, and breast or colon cancer.2 Physical inactivity is a risk factor for many diseases. However, even a formerly inactive patient who has been diagnosed with a disease such as chronic heart failure (CHF) can substantially benefit from becoming physically active, which is of particular relevance for cardiac rehabilitation. As a physician in a rehabilitation hospital, I regularly see patients who used to be physically inactive making their first steps towards lifestyle changes such as engaging in physical exercise during hospitalization.

Both the Research Highlight by King1 and studies published in the medical literature have important practical implications for cardiac rehabilitation. For example, a prospective cohort study involving healthy participants in Taiwan demonstrated that even a small amount of regular exercise (92 min per week) led to a significant increase in life expectancy.3 In addition, evidence exists that supervised exercise results in better outcomes than primary stenting in patients with peripheral artery disease.4 This finding supports an association between exercise and improved vascular endothelial function owing to reduced intima–media thickness.5 Anabolic effects and improved muscular function have been demonstrated with exercise in patients with advanced CHF.6 Additional evidence stems from an exercise-related reduction of E3 ubiquitin-protein ligase TRIM63 (also known as MuRF-1) in the setting of CHF.7 MuRF-1 contributes to proteolysis in muscle wasting,7 to which patients with CHF are particularly vulnerable. Evidence also exists that exercises incorporating balance and strength training lead to a significant reduction in the number of falls among healthy elderly people (aged ≥70 years).8 Balance and strength training will also prevent muscular atrophy, osteoporosis fractures, and secondary illness owing to inactivity after a fall.

In my daily clinical routine, I frequently make the discovery that formerly physically inactive patients with insulin-dependent type 2 diabetes require fewer insulin units after they start exercising. Similarly, patients participating in individualized exercise programs tend to show improvements in the 6-min walk test, pulse oxymetry, and arterial blood gases. Therefore, supporting patients in the continuation of physical exercise after their release from the rehabilitation hospital is a vital component of care.