Sitting, squatting, and the evolutionary biology of human inactivity

• DOI: 10.1073/pnas.1911868117
• Publication Date: 2020-03-10T00:29:33Z
• Authors: David A. Raichlen; Herman Pontzer; Theodore W. Zderic; Jacob A. Harris; Audax Z. P. Mabulla; Marc T. Hamilton; Brian M. Wood
• Keywords: Adult; Male; Adolescent; 1.1 Normal biological development and functioning; Posture; physical activity; Cardiovascular; hunter-gatherer; Young Adult; 03 medical and health sciences; sedentary; 0302 clinical medicine; Clinical Research; Underpinning research; cardiovascular disease; Health Sciences; Accelerometry; Humans; Muscle, Skeletal; Metabolic and endocrine; posture; Prevention; 501; Skeletal; Middle Aged; Biological Evolution; 3. Good health; Good Health and Well Being; Muscle; Female; Public Health; Sedentary Behavior

Significance Inactivity is a growing public health risk in industrialized societies, leading some to suggest that our bodies did not evolve to be sedentary. Here, we show that, in a group of hunter-gatherers, time spent sedentary is similar to that found in industrialized populations. However, sedentary time in hunter-gatherers is often spent in postures like squatting that lead to higher levels of muscle activity than chair sitting. Thus, we suggest human physiology likely evolved in a context that included substantial inactivity, but increased muscle activity during sedentary time, suggesting an inactivity mismatch with the more common chair-sitting postures found in contemporary urban populations.