SARS-CoV-2/COVID-19 and physical distancing: risk for circadian rhythm dysregulation, advice to alleviate it, and natural experiment research opportunities.

SARS-CoV-2/COVID-19 leads to numerous unplanned or natural experiments with health and disease. Physical (social) distancing - a counter-measure with no alternative, but with no precedence in scope and scale either - is a key intervention and trigger of natural experiments. From a practical perspective, concerned disciplines should increase awareness of, provide recommendations to meet, and develop research for, health challenges arising from physical distancing at home. From the field of chronobiology, prolonged home stays may place undue strain on the body's circadian timing system but straightforward and often underestimated advice for coping can be provided (herein we provide such advice). Of course, advice or recommendations from other concerned disciplines that identify challenges associated with current COVID-19 mitigation strategies are also needed. From a research perspective, different disciplines should rise to the occasion and explore unsuspected natural experiment angles toward novel insights to promote health and prevent disease.