We are looking for 12 participants to participate in our new pilot study. Recruitment has started. Please sign up now via the link below, if you are interested. The study runs from the 12. April to 11. May 2024. For more information, please read the text below and our flyer: GoGarmin Recruitment Flyer. The biological clock…
The results of our study on the effects of near-infrared light (NIR) on health and well-being in people suffering from sleep loss is published today. In a double-blind, randomized, placebo-controlled study, the effects of three NIR light (850 nm) doses (1, 4, or 6.5 J·cm−2) were examined against the placebo. Exposure was presented five days…
Kick off meeting Healthy Living as a service in Martiniplaza. Our goal in this project is to contribute with knowledge on 24-hour rhythms and sleep. Michelle Luxwolda and Rieks Hoekman organised a presentation of Chrono@Work in a booth. The audience could indicate their sleep pattern to create a chronotype distribution in a creative way!
Chrono@Work received the good news that funding was granted for a project in the topic PCH (personalized & connected health) Ecosystem from the University Medical Center Groningen. This is a European funded project under the umbrella of SNN. In the project, Chrono@Work, supported by the University of Groningen, will develop a mobile application to use…
Last week, I was asked several times to talk again about the role of the biological clock for our health and the detrimental effects of Daylight Saving time. It is all about healthy sleep and the right light at the right time. Prevention of sleep problems is the most important thing. But if you suffer…
Can we bring in a bit of sunshine? After 2 successful rounds of the Light Study last summer and winter, we have decided to extend the study into near-infrared light one more time to the coming winter period. This is the first-ever long-term study into the effects of pulsed near-infrared (NIR) light on human well-being…
Marijke Gordijn is invited for several public events (in Dutch) on the topic of Daylight saving time. The first one will be an interview organised by Studium Generale Utrecht in collaboration with Tivoli/Vredenburg. On October 28th, at 8:15 pm on the stage of Tivoli-Vredenburg in Utrecht, Marijke will talk about the role of the biological…
Marijke Gordijn from Chrono@Work will be moderating two great speakers at deLIGHTed Talks Good Light – Good Life in Wintertime online on November 3rd, 2021: Prof. Till Roenneberg will explain how chronobiologists think about daylight saving time and what would be the most optimal choice for our health. Dr. Manuel Spitschan will explain how to…
Normally we promote to sleep at night and be awake during the day. However, Marijke Gordijn from Chrono@Work accepted the invitation to be one of the two guests in the night program De Slapelozen on Dutch radio on early Thursday morning August 12th 2021, between 2 and 4 am. The reason why is that during…
On January 8th, Marijke Gordijn from Chrono@Work and Roelof Hut from the University of Groningen were interviewed by EditieNL about the effects of the COVID-19 related restrictions on sleep. Colleagues recently published that on average people sleep longer and later during the lockdown. However, shortage of sleep and sleeping problems have serious health effects. EditieNL…
In the early morning of December 26th, Marijke Gordijn from Chrono@Work gave an interview on NPO Radio 1 about the role of light for well being and health. This item is especially interesting in the dark winter days around Christmas in our region. The focus of the interview was on the new study we do…
Can we bring in a bit of sunshine? After 2 successful rounds of the Light Study last summer and winter, we have decided to extend the study into near-infrared light one more time to the coming winter period. This is the first-ever long-term study into the effects of pulsed near-infrared (NIR) light on human well-being…
The COVID-19 pandemic poses a serious health threat to the world population. In response, governments are implementing a variety of new policies including self-quarantine, self-isolation and social distancing. While medically necessary to limit spread, these new social policies can disrupt many of the stabilizing factors in our lives which support mental health. In close collaboration,…
The policies to limit spreading of COVID-19 is ‘stay home’ and ‘work from home’. The consequence is that most people see very little daylight. While it is very important to stay home as much as possible and keep ‘social distance’ all the time, in the Netherlands it is not forbidden to go outside. The Dutch…
Chrono@Work will be present at several symposia, classes and congresses in the upcoming period. Please have a look and subscribe if you are interested in the topic. 16th April 20:00h in Leeuwarden: Studium Generale Het Einde van de Zomertijd en Dan? 18th April whole day in Zeist: Medilex symposium on ‘Slaapproblemen en -stoornissen bij mensen met…
The European Parliament voted on March 26th this year in Strasbourg in favour of abolishing the bi-annual change in clock time. From Saturday 30th to Sunday 31st of March 2019, the clock will move forward by one hour to Central European Summertime, but from 2021 the parliament will no longer want these changes to take…
Chrono@Work published a paper on the role of the biological clock in safety and health in the Dutch journal for health and safety officers: Safety! magazine. In this paper, we explain why we perform so badly during the night and how we can keep our biological clock in synch with the natural rhythm of light…
On November 7th, NTR presented a documentary FOCUS on the health risks of working at night and discusses possible solutions. In accordance with the reports of the Dutch Health Council 2015 and 2017, the most important point is to avoid working at night as much as possible. Roelof Hut from the University of Groningen and…
Last weekend Daylight saving time 2018 ended and Europe went back to Central European Time. In a short movie commissioned by the University of Groningen, Marijke Gordijn explained once more why for us, in the Netherlands, the current time we have in winter is the most optimal choice. In fact, The Netherlands should even be…
Linda Geddes, journalist in the UK, published an article in the Guardian titled “No more snooze button: a complete guide to waking up feeling fantastic“. “Now the clocks have gone back and the days are getting shorter, it can be hard to get out of bed. But, from dawn simulators to a regular wakeup time,…
In August, the European Union voted to abolish the bi-annual change in clock time. `Whether the continent will be in constant ‘wintertime’ or ‘summertime’ remains to be decided and this imposes a lot of debate in the various countries of the European Union. Chrono@Work is actively involved in international and national discussion. International and Dutch…
Marijke Gordijn from Chrono@Work co-authors a paper, published in Scientific Reports, about how the eye uses natural light information to synchronize the biological clock to the outdoor light, even when clouds are covering the sky. The mammalian circadian system encodes both absolute levels of light intensity and color to phaselock (entrain) its rhythm to the…
Chrono@Work is proactive in spreading scientific arguments for a thoughtfull decision on stopping summer/wintertime. Now that the EU recommends to end changing our clocks twice a year, each country has to decide what to do. The recommendation from the EU is based on years of discussions with and within the parliament and triggered by the outcome…
Invited by Honeywell and Medilux, Chrono@Work gave a lecture in Muscat (Oman) on ‘human solutions for control rooms’. In between very technical lectures and for a very special, interested audience, we talked about putting the human in the center of attention. What can we do to optimize the 24h environment for people working 24/7 in…
On May 17th, Pauline Bollen and Marijke Gordijn from Chrono@Work organized an interactive workshop for a group of 15 social workers of academic institutes in the Netherlands. The assignment was clear: inform us on possible sleep problems we may encounter in our office and how to proceed if we recognize some. The 3h-workshop consisted of…
Chrono@Work B.V. Groningen is the first company this year to receive a grant of € 25,000 of SNN. The innovation grant for the Groningen company is intended for research into the feasibility of a sensor system that teaches poor sleepers to sleep according to their biological clock. Read more on the site of SNN. With…
Chronobiologists are not in favour of shifting the social clock backwards and forwards twice a year, because of negative effects on sleep and other possible harmful health effects. In the news section of this website the subject has often been discussed. In recent years, the number of advocates for abolishing summertime completely has grown, and…
As a member of the Committee Nightwork, Marijke Gordijn contributed to a new publication of the Health Council of the Netherlands: Health Risks of night shift work. In the Netherlands about 1.3 million people sometimes or regularly work at night. Night shift work disrupts the day-night rhythm of the body, which may lead to adverse…
In the Dutch Television program ‘Dokters van Morgen‘ on October 17th, Antoinette Herzenberg pays attention to the importance of a healthy sleep. As part of the program, five volunteers went camping during one weekend. Chrono@Work supported the program with scientific input and the analysis of light exposure, rest-activity rhythms and melatonin patterns. Following up on…
Marijke Gordijn is a co-author of a study featured at Sleep. Study objectives To determine the effect of light exposure on subsequent sleep characteristics under ambulatory field conditions. Methods Twenty healthy participants were fitted with ambulatory PSG and wrist-actigraphs to assess light exposure, rest-activity, sleep quality, timing and architecture. Laboratory salivary dim-light melatonin onset (DLMO)…
Wams, E.J., Woelders, T., Marring, I., Van Rosmalen L., Beersma, D.G.M., Gordijn, M.C.M. & Hut R.A. Linking light exposure and subsequent sleep: a field EEG study in humans. SLEEP 40 (12): zsx165 (2017)
https://doi.org/10.1093/sleep/zsx165
The Dutch media are highly interested in the new teaching package Charge Your Brainzzz. Please read the item “50% of the adolescents do not sleep enough…but in this way you will get them in bed” (in Dutch) that RTL published online on September 27th.
After a year of hard work we are there! The teaching materials for the package Charge Your Brainzzz are ready. Charge your Brains teaches highschool students about sleep. On 27 September, Chrono@Work and the Dutch Brain Foundation will launch this special educational package. Charge Your Brainzzz is a modern package with activating learning tools including…
Van der Heijden, K.B., Vermeulen M.C.M., Donjacour, C., Gordijn M., Hamburger, H., Meijer, A.M., Van Rijn, K. Chronic sleep reduction predicts academic achievement and study concentration in higher education students. J. Sleep Res. 2017
http://onlinelibrary.wiley.com/doi/10.1111/jsr.12596/abstract
Wednesday September 27th, Chrono@Work and the Brain Foundation will launch the new teaching material Charge Your Brainzzz in the Corpus Congress Centre in Leiden. Charge Your Brainzzz consists of a package of three lessons about sleep regulation and sleep disorders, with activating learning tools, animations (to be used during class) and a serious game developed…
In continuation of SLAAP2016, the second Dutch Sleep Congress will be organized again this year under the umbrella of the Dutch Society for Sleep-Wake research (NSWO) and the Sleep Medicine Association Netherlands (SVNL) in the Heerlickheijd in Ermelo. SLAAP 2017 is a unique collaboration between the various disciplines who work in the field of Sleep, such…
We sleep more than one third of our lives. And that’s for a reason: sleep is important for our everyday functioning. If you sleep badly, you have less energy and you can hardly concentrate. There are many ways to learn to sleep better. The Dutch Brain Foundation and Chrono@Work have asked Grendel Games to develop…
On May 16, Chrono @ Work organizes 2 workshops for Ambulance Care Netherlands in the Rijtuigenloods in Amersfoort. These workshops are part of the program ‘Sustainable employability: Optimal on the go!’ Both workshops are fully booked. During the workshop attention is given to the care for the ambulance workers themselves. How to deal with the…
Woelders T., Beersma D.G.M., Gordijn M.C.M., Hut R.A. & Wams E.J. Daily light exposure patterns reveal phase and period of the human circadian clock. J. Biol. Rhythms 2017
http://journals.sagepub.com/doi/abs/10.1177/0748730417696787
Bruinenberg, V.M., Gordijn, M.C.M., MacDonald, A., Van Spronsen, F.J., Van der Zee, E. Sleep disturbances in Phenylketonuria: an explorative study in men and mice. Frontiers in Neurology, section Sleep and Chronobiology. vol. 8:167 (2017).
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5405067/
What is sleep? Sleep as part of our daily life, This chapter describes the basic principles of sleep and wake regulation, the effects of sleep deprivation due to a mismatch between sleep and the biological clock, and what you can do about it. Every evening, a large behavioral change occurs in almost all people. In…
Gordijn M.C.M. Slapen als onderdeel van een gezonde leefstijl. In: “Gestoorde slaap: een onschuldig probleem?” Lancel M., Koenraadt F. en ‘t Lam K. (eds). Wolf Legal Publishers. pp 13-28. (2016).
Chronotherapeutic interventions Marijke Gordijn of Chrono@Work co-authored a Dutch paper on Chronotherapeutic interventions in Psychiatry. She wrote this paper together with 3 colleagues with whom she also started Chronotherapy Network Netherlands (www.cnn.nl). The paper was published in the continuing education journal Psyfar. Since 2006, Psyfar focusses on educating and testing psychiatrists, hospital pharmacists, geriatrics specialists,…
Meesters Y., Gordijn, M.C.M., Spaans H.P., Verwijk E. Chronotherapeutische interventies. Psyfar 11(4): 18-25. (2016).
Chrono@Work’s employee Marina Giménez is the first author of a paper describing a study on the effects of a new dynamic room lighting system on sleep of patients admitted to a cardiology ward. Irregular 24 h light/dark cycles with night-time light exposure and a low amplitude are disruptive for sleep, mood and circadian rhythms. Nevertheless,…
According to the European directives, Daylight Saving time ends in the last weekend of October. Most European countries follow this directive, which means that this year on October 30 the clock will be shifted back one hour (change from 3 am to 2 am). For us this means an extra hour on the night of…
On September 12 several media reported that according to a TNS Nipo survey among 3,400 Dutch, that one out of six workers has sleeping problems. In a radio interview with Radio North on September 12 at 13: 40h Marijke Gordijn CEO of Chrono@Work explained what the risks are of sleep deprivation (http://radio.rtvnoord.nl/ipad/index.asp?actie=radiogemist). We should distinguish…
In their issue No. 19 of 23 August – 6 september, Computer Idee, a magazine about computers and electronics for consumers, pays detailed attention to the pros and cons of blue light filters for computers, tablets and smartphones. The conclusion is that we are exposed to more blue light through the use of electronic screens…
LIght therapy to shift the biological clock has been shown to be effective, but in most cases studies are carried out in well controlled laboratory studies and with long duration light pulses. In practice, light therapy should consist of an easy to apply lighting regime to which people at home will adhere and with clear…
Marijke Gordijn CEO of Chrono@Work will give a lecture on Wednesday, July 13th at the satellite symposium entitled ARE MOOD DISORDERS CHRONOBIOLOGICAL DISORDERS? This satellite symposium is organized by the Society for Light Treatment and Biological Rhythms on the first day of the 18th Annual Conference of The International Society for Bipolar Disorders (ISBD16) held…
Chrono@Work wrote an informative article in the journal of “Longkruid” of the Dutch Society for Pulmonary Function Analysts. Breathing and sleep are two essential elements of our daily life that, if everything is working correctly, we barely notice. But if something goes wrong, it has a great impact on our daily lives, our work and…
Marijke Gordijn CEO of Chrono@Work will give a lecture on Thursday 30th of June entitled: “How to set light and dark for personal and work schedules” as part of the teaching course of SLTBR in New York. http://sltbr.org/event/sltbr-meeting-2016/
Light pulses of 30 min. in the morning on three consecutive days, in a home setting, in combination with dim light during the evenings, can be part of an efficient phase advancing chronotherapy protocol to shift the biological clock. It is well known from controlled laboratory experiments, that light in the morninge induces phase shifts of the biological…
NRC next fact check, examines whether the NRC report in the Algemeen Dagblad of 9 May over Duch being campions at sleeping long is correct. The conclusion was drawn on the basis of an article in Science Advances which made use of data from the worldwide used sleepapp. NRC Next consulted among others, Chrono@Work on this…
Apple recently released a free update to iOS 9.3, the operating system for iPhone and iPad. The most interesting addition this time is the ‘night shift’ function. After sunset, the screen gets a rosy glow that is less bothersome to the eyes and should ensure a better night’s sleep. In the Dagblad van het Noorden…
Under the umbrella of the Dutch Association of Sleep-Wake Research (NSWO) and the Sleep Medicine Association Netherlands (SVNL) the first Dutch Sleep Congress, SLEEP 2016.will be organized on the 3-4 November, 2016 in the Heerlickheijd, Ermelo. The conference is a unique interdisciplinary collaboration between different departments working in the field of Sleep, e.g. pulmonologists, neurologists,…
Light of short wavelengths has been shown to play a key role in non-image forming responses. Due to aging, the ocular lens becomes more yellow reducing the transmission of short wavelengths in the elderly. In the present study, we make use of cataract surgery to investigate the effects of a relative increase of short wavelength transmission on melatonin-…
Geerdink, M., Walbeek, T. J., Beersma, D. G. M., Hommes, V., & Gordijn, M. C. M. Short Blue Light Pulses (30 Min) in the Morning Support a Sleep-Advancing Protocol in a Home Setting. J. Biol. Rhythms 31(5): 483 – 497 (2016).
As the 24-hour economy continues to leave its mark on societal life, the effects of the disruption of the natural biological rhythm become more apparent. Aside from the effects this has on sleep we will also discuss the health effects in the long term. As well as potential measures to reduce the negative effects of…
This study examined associations of chronotype and age with shift-specific assessments of main sleep duration, sleep quality and need for recovery in a cross-sectional study among N ¼ 261 industrial shift workers (96.6% male). Logistic regression analyses were used, adjusted for gender, lifestyle, health, nap behaviour, season of assessment and shift schedule. Shift workers with latest versus earliest…
Light is an important environmental stimulus for the entrainment of the circadian clock and for increasing alertness. The intrinsically photosensitive ganglion cells in the retina play an important role in transferring this light information to the circadian system and they are elicited in particular by short-wavelength light. Exposure to short wavelengths is reduced, for instance, in elderly…
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…
