The biological clock modulates the human cortisol response in a multiplicative fashion

Human cortisol levels follow a clear circadian rhythm. We investigated the contribution of alternation of sleep and wakefulness and the circadian clock, using forced desynchrony. Cortisol levels were best described by a multiplication of a circadian and a wake-time component. The human cortisol response is modulated by circadian phase. Exposure to stress at an unnatural phase, as in…

Short-wavelength attenuated polychromatic white light during work at night: limited melatonin suppression without substantial decline of alertness

Van de Werken, M., Giménez, M. C., de Vries, B., Beersma, D. G. M., & Gordijn, M. C. M. Short-wavelength attenuated polychromatic white light during work at night: limited melatonin suppression without substantial decline of alertness. Chronobiology International, 30(7), 843–854. (2013).

‘The optimal working schedule is different for everyone.’

‘The optimal working schedule is different for everyone.’ Increasingly, Dutch businesses are looking for ways to increase health of their shift workers, according to chronobiologist Marijke Gordijn of the Univerity of Groningen. Her company Chrono@Work increasingly gets asked about what to do concerning workplace lighting, food patterns and the right way to schedule personnel. Gordijn…