Effects of Daylight and Physical Activity on Sleep and Circadian Rhythm
Official title: Beneficial Effects of Daytime Light Exposure and Physical Activity on the Human Circadian Clock and Sleep
Run by University Hospital, Basel, Switzerland · NCT05513547 · Data updated 2026-05-14
This study is no longer in our active list. It may have stopped recruiting or finished. The details below are as of 2026-05-14 and are kept for reference. Check ClinicalTrials.gov for its current status, or see similar studies below.
This study is testing how different types of daylight and physical activity can help people sleep better and adjust their body clocks.
Quick facts
| Study type | Interventional |
|---|---|
| Ages | 18 Years to 35 Years |
| Sex | All |
| Enrollment | 48 (estimated) |
| Sponsor | University Hospital, Basel, Switzerland Academic / other |
| Locations | 1 site (Basel) |
| Trial ID | NCT05513547 on ClinicalTrials.gov |
Is this trial a fit for you?
✓Likely a good fit
Ideal candidates for this study are healthy adults aged 18-35 with a normal body mass index and moderate physical activity levels.
✕Probably not a fit
Patients with chronic sleep disorders or significant medical conditions may not benefit from this study.
A plain-English reading of the study's rules. Only the study team can confirm whether you qualify.
What this trial studies
This study investigates how exposure to different types of daylight and levels of physical activity can shift the human circadian clock and improve sleep quality. Participants will experience three different light conditions during the day and will be assigned to either a hiking activity or a rest period. The primary endpoint is the change in dim-light melatonin onset (DLMO), which will help determine the impact of these interventions on sleep. The study aims to clarify the roles of various light wavelengths and physical activity on the biological clock and sleep patterns.
Why it matters
Potential benefit: If successful, this study could lead to improved sleep quality and circadian rhythm regulation for individuals exposed to inadequate light conditions.
How similar studies have gone: Other studies have shown promising results in improving sleep and circadian rhythms through light exposure and physical activity, suggesting this approach may be effective.
Who can join: the full rules
Show full inclusion / exclusion criteria
Inclusion Criteria: * Age: 18-35 years * Body Mass Index: 18.5-24.9 (i.e., normal weight according to World Health Organization (WHO) criteria) * Moderate cardiorespiratory fitness levels, moderate level of endurance training according to the category "moderate physical activity" (category 2) of the International Physical Activity Questionnaire (IPAQ) short form * Informed consent as documented by signature of the participant Exclusion Criteria: * Self-reported pregnancy * Investigator's family members, employees, or other dependent persons * Chronic or debilitating medical (including psychiatric) conditions; normal state of health will be established on the basis of questionnaires and the examination by the physician in charge. Illnesses that would be a reason for exclusion are: * Sleep disorders: Narcolepsy, sleep apnea (apnea index \> 10), periodic limb movements (PLM index \> 15), insomnia (polygraphically recorded sleep efficiency \< 70% or Pittsburgh Sleep Quality Index (PSQI) index \> 5), hypersomnia * Chronobiological disorders: hypernychthemeral sleep-wake cycle, delayed or advanced sleep phase syndrome * Psychiatric disorders * Somatic diseases: cardiovascular, respiratory, gastrointestinal, haemopoietic, visual and immune system diseases, neurological disorders, infectious diseases, allergies (e.g., skin allergies, acute hay fever), thrombocytopenia or other dysfunctions of blood platelets * Drug use: volunteers must not consume any drugs (including nicotine and alcohol) for the entire duration of the study with no history of drug or alcohol dependency. This will be ensured by the use of a urine multi-drug screen at every experimental visit. * Medication that could affect outcome parameters * Shift work \< 3 months prior to study intake * Transmeridian travel (\> 2 time zones) \< 1 month prior to study intake * Extreme chronotype (Munich Chronotype Questionnaire \[MCTQ\] \<2 or \>7) * Extremely long/short sleep duration (subjective sleep duration on workdays outside 6-10h according to the MCTQ) * Abnormal colour vision, vision disorders (other than e.g., mild myopia corrected with contact lenses) * Inability to understand and/or follow procedures * Non-adherence to the circadian stabilization protocol during the five days prior to and between the experimental visits (deviation of \>30min form scheduled times more than twice or on the day of the study visit)
Where it's running
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Centre for Chronobiology, Psychiatric Hospital of the University of Basel
Basel, Switzerland Recruiting
Study contacts
- Principal investigator: Christine Blume, Dr. med. — Centre for Chronobiology, Psychiatric Hospital of the University of Basel
- Study coordinator: Christine Blume, Dr. med.
- Email: christine.blume@upk.ch
- Phone: +41 (0)61 325 5074
How to take part
- Review the eligibility criteria above with your treating physician.
- Check the official listing on ClinicalTrials.gov for the latest contact details and recruitment status.
- Contact the study coordinator or principal investigator to ask for pre-screening. Pre-screening is free and never obligates you to enroll.