Resetting the late timing of ‘night owls’ has a positive impact on mental health and performance

TY - JOUR

T1 - Resetting the late timing of ‘night owls’ has a positive impact on mental health and performance

AU - Facer-Childs, Elise

AU - Middleton, Benita

AU - Skene, Debra

AU - Bagshaw, Andrew

PY - 2019/8

Y1 - 2019/8

N2 - There is conflict between living according to our endogenous biological rhythms and our external environment, with disruptions resulting in negative consequences to health and performance. This is often documented in shift work and jet lag, but ‘societal norms’ e.g. typical working hours, can create profound issues for ‘night owls’, people whose internal biological timing predisposes them to follow an unusually late sleep-wake cycle. Night owls have also been associated with health issues, mood disturbances, poorer performance and increased mortality rates. This study used a randomized control trial design aimed to shift the late timing of night owls to an earlier time (phase advance), using non-pharmacological, practical interventions in a real-world setting. These interventions targeted light exposure (through earlier wake up/sleep times), fixed meals times, caffeine intake and exercise. Overall, participants demonstrated a significant advance of ∼2 h in sleep/wake timings as measured by actigraphy and circadian phase markers (dim light melatonin onset and peak time of the cortisol awakening response), whilst having no adverse effect on sleep duration. Importantly, the phase advance was accompanied by significant improvements to self-reported depression and stress, as well as improved cognitive (reaction time) and physical (grip strength) performance measures during the typical ‘suboptimal’ morning hours. Our findings propose a novel strategy for shifting clock timing towards a pattern that is more aligned to societal demands that could significantly improve elements of performance, mental health and sleep timing in the real world.

AB - There is conflict between living according to our endogenous biological rhythms and our external environment, with disruptions resulting in negative consequences to health and performance. This is often documented in shift work and jet lag, but ‘societal norms’ e.g. typical working hours, can create profound issues for ‘night owls’, people whose internal biological timing predisposes them to follow an unusually late sleep-wake cycle. Night owls have also been associated with health issues, mood disturbances, poorer performance and increased mortality rates. This study used a randomized control trial design aimed to shift the late timing of night owls to an earlier time (phase advance), using non-pharmacological, practical interventions in a real-world setting. These interventions targeted light exposure (through earlier wake up/sleep times), fixed meals times, caffeine intake and exercise. Overall, participants demonstrated a significant advance of ∼2 h in sleep/wake timings as measured by actigraphy and circadian phase markers (dim light melatonin onset and peak time of the cortisol awakening response), whilst having no adverse effect on sleep duration. Importantly, the phase advance was accompanied by significant improvements to self-reported depression and stress, as well as improved cognitive (reaction time) and physical (grip strength) performance measures during the typical ‘suboptimal’ morning hours. Our findings propose a novel strategy for shifting clock timing towards a pattern that is more aligned to societal demands that could significantly improve elements of performance, mental health and sleep timing in the real world.

KW - late circadian phenotypes

KW - chronotype

KW - actigraphy

KW - dim light melatonin onset

KW - cortisol awakening response

KW - non-pharmacological interventions

KW - phase advancing

KW - depression

KW - stress

KW - performance

UR - http://www.scopus.com/inward/record.url?scp=85067070284&partnerID=8YFLogxK

U2 - 10.1016/j.sleep.2019.05.001

DO - 10.1016/j.sleep.2019.05.001

M3 - Article

VL - 60

SP - 236

EP - 247

JO - Sleep Medicine

JF - Sleep Medicine

SN - 1389-9457

ER -