Does a daily one-hour clock delay change your body clock?
The Effect of a Continuous 1-Hour Time Delay on Circadian Rhythms
NA · University of Aarhus · NCT07317349
We will test whether living with a one-hour daily time delay for five days shifts the body clock of healthy adults aged 23-45 who participate with their cohabiting partner.
Quick facts
| Phase | NA |
|---|---|
| Study type | Interventional |
| Enrollment | 40 (estimated) |
| Ages | 23 Years to 45 Years |
| Sex | All |
| Sponsor | University of Aarhus (other) |
| Locations | 1 site (Aarhus) |
| Trial ID | NCT07317349 on ClinicalTrials.gov |
What this trial studies
This in-laboratory protocol enrolls healthy cohabiting heterosexual couples who maintain a fixed daily routine while experiencing a continuous one-hour daily time delay over five days. Both partners must meet screening criteria including a normative chronotype, regular sleep-wake timing, low seasonality, and absence of sleep or mood disorders. The laboratory setting controls routine and timing so participants' circadian timing can be tracked across the manipulation. The design isolates the effect of a small, repeated clock delay on internal circadian rhythms in a controlled environment.
Who should consider this trial
Good fit: Healthy adults aged 23-45 who live with a partner and can commit to a five-day in-laboratory protocol, have regular sleep schedules, no sleep or mood disorders, and meet the study's chronotype and education requirements are ideal candidates.
Not a fit: People who work night shifts, have recent or imminent transmeridian travel, extreme chronotypes, or diagnosed neurological, psychiatric, sleep, or mood disorders are unlikely to benefit or be eligible.
Why it matters
Potential benefit: If successful, this could clarify how small, repeated daily time shifts affect sleep timing and circadian alignment and inform ways to reduce disruption from schedules like daylight saving or irregular work hours.
How similar studies have performed: Previous work shows that light exposure, shift work, and time-zone changes can shift circadian rhythms, but applying a continuous one-hour daily delay in a tightly controlled lab with cohabiting couples is relatively novel.
Eligibility criteria
Show full inclusion / exclusion criteria
Inclusion Criteria * Healthy adults aged 23-45 years * Part of a heterosexual, cohabiting couple willing to participate together in a five-day in-laboratory study * Both partners meet all inclusion criteria * Completion of at least upper-secondary education * Maintain a regular sleep-wake schedule * Habitual sleep timing within a normative range (non-extreme chronotype), assessed using the Morningness-Eveningness Questionnaire (MEQ) or the Munich Chronotype Questionnaire (MCTQ) * Both partners fall within the acceptable chronotype range to ensure aligned sleep-wake patterns * Low seasonality scores on the Seasonal Pattern Assessment Questionnaire (SPAQ) * Free from underlying sleep or mood disorders Exclusion Criteria * Engages in night-shift work or maintains an irregular work or sleep schedule * International travel involving a time-zone change of more than two hours within the past two months, or anticipated travel before study completion * Diagnosed neurological, psychiatric, or sleep disorder (e.g., insomnia, sleep apnea, bipolar disorder) * High risk of sleep apnea, defined as a Berlin Questionnaire score \>2 (Lauritzen et al., 2018) * Use of medications known to affect sleep, alertness, melatonin secretion, or circadian timing * Unable or unwilling to comply with behavioral restrictions, including refraining from electronic devices displaying time cues unless clocks are removed and devices are disconnected from Wi-Fi * Unable or unwilling to comply with consumption restrictions, including abstaining from caffeine, alcohol, and melatonin-rich foods during the study * Extreme chronotype, defined as a habitual midsleep time outside 03:00-05:00 on the MCTQ or classification as an extreme morning or extreme evening type on the MEQ * Daily caffeine consumption exceeding 400 mg (approximately 4-5 cups of coffee) * Current smoker or smoking within the past six months
Where this trial is running
Aarhus
- Aarhus University, Department of Psychology and Behavioural Sciences — Aarhus, Denmark (RECRUITING)
Study contacts
- Study coordinator: Ali Amidi, PhD
- Email: ali@psy.au.dk
- Phone: +4587165305
How to participate
- Review the eligibility criteria above with your treating physician.
- Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
- Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions: Circadian Rhythms, Time Perception, Sleep, circadian phase delay, Healthy adults