Night Owls Can Retrain Their Internal Clocks

Over a 3 week period a team of international researchers showed it was possible to shift the circadian rhythm of night owls using non-pharmacological and practical interventions; participants were able to bring their sleep/wake timings forward by 2 hours while having no negative effects on sleep duration; participants reported decreased feelings of depression, stress, and daytime sleepiness.

"Our research findings highlight the ability of a simple non-pharmacological intervention to phase advance 'night owls', reduce negative elements of mental health and sleepiness, as well as manipulate peak performance times in the real world.” says Dr. Elise Facer-Childs.

Night owls are those whose internal body clock dictates later than usual sleep/wake times, in this study participants had an average bedtime of 2:30AM and wake time of 10:15AM. Disturbances to the circadian system have been linked to a range of health issues including increased morbidity and mortality rates, mood swings, and declines in cognitive and physical performance.

"Having a late sleep pattern puts you at odds with the standard societal days, which can lead to a range of adverse outcomes -- from daytime sleepiness to poorer mental wellbeing.” says Dr. Andrew Bagshaw.

"We wanted to see if there were simple things people can do at home to solve this issue. This was successful, on average allowing people to get to sleep and wake up around two hours earlier than they were before. Most interestingly, this was also associated with improvements in mental wellbeing and perceived sleepiness, meaning that it was a very positive outcome for the participants. We now need to understand how habitual sleep patterns are related to the brain, how this links with mental wellbeing and whether the interventions lead to long-term changes."

For a period of three weeks 22 healthy participants in the experimental group were asked to 1) wake up 2-3 hours before regular wake up time and maximise outdoor light in the morning; 2) go to bed 2-3 hours before habitual bedtime and limit light exposure at night; 3) keep wake/sleep times fixed on work days and free days; and 4) eat breakfast as soon as possible after waking up, eat lunch at the same time every day, and refrain from eating after 7PM.

Participants were observed to have increases in cognitive reaction time and physical grip strength performance during the morning when night owls often have high levels of tiredness, as well as a shift in peak performance times from evening to afternoon. The intervention also increased the number of days participants consumed breakfast and led to better well being with participants reporting decreases in feelings of depression and stress.

"Establishing simple routines could help 'night owls' adjust their body clocks and improve their overall physical and mental health. Insufficient levels of sleep and circadian misalignment can disrupt many bodily processes putting us at increased risk of cardiovascular disease, cancer and diabetes," says Professor Debra Skene.

Compared to morning larks night owls tend to be more common in society due to having to fit sleep to busy work and school schedules that are out of sync with their preferred patterns. The researchers suggest this intervention could also be applied to other settings such as industry or sporting sectors which focus on developing strategies to maximise productivity and optimise performance at certain times and in different conditions.

"By acknowledging these differences and providing tools to improve outcomes we can go a long way in a society that is under constant pressure to achieve optimal productivity and performance.”