Mixed
Physical inactivity is a primary, direct cause of most chronic diseases, acting through distinct biological mechanisms that differ from those of exercise, rather than merely being the absence of exercise.
Stop viewing inactivity as merely 'not exercising.' It is an active biological state that rapidly degrades health (e.g., insulin sensitivity drops within days, vascular function changes immediately). To prevent chronic disease, you must actively counteract inactivity with regular physical activity, as the mechanisms of harm from sitting are distinct from the benefits of exercise.
Conclusive evidence exists that physical inactivity is one important cause of most chronic diseases. In addition, physical activity primarily prevents, or delays, chronic diseases... mechanisms by which inactivity causes disease differ from mechanisms by which physical activity is a therapy/treatment to act as a primary preventer of disease.
Why this rating
Based on a comprehensive review of historical, epidemiological, and mechanistic studies including bed rest trials and human step-reduction studies.
Source
Lack of Exercise Is a Major Cause of Chronic Diseases
Frank W. Booth et al. · Comprehensive physiology · 2012
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