Heart Rate, Sleep
Conditions
Keywords
Mindfulness, Sleep Efficiency, Heart Rate Variability
Brief summary
This study tested whether a 10-day smartphone app-based mindfulness program can improve sleep and reduce physiological stress in healthy adults. Eighty-one healthy adults were randomly assigned to either a mindfulness group (completing a daily 10-minute guided session via the Ōura app for 10 days) or a waitlist control group. All participants wore an Ōura Ring throughout the study to objectively measure sleep and heart rate variability (HRV). Questionnaires on perceived stress, sleep quality, burnout, and mindfulness were completed before, immediately after, and four weeks after the intervention. The study was conducted at the University of Southern Denmark.
Detailed description
This randomized controlled trial (RCT) used a waitlist-controlled design to examine whether a 10-day smartphone app-based mindfulness program could improve sleep and reduce physiological stress markers in healthy adults. The study was embedded within a broader 4-month longitudinal cohort study (N=140); the RCT sub-study focused on participants in the low-stress stratum (Perceived Stress Scale \[PSS-10\] ≤13) at screening. Participants (n=81) were randomized in approximately a 3:2 ratio to either a mindfulness intervention group (n=49) or a waitlist control group (n=32). The mindfulness group completed one 10-minute guided audio session daily ("destress" module, narrated by Headspace) delivered via the Ōura app for 10 consecutive days in free-living conditions at a time of their own choosing. Compliance was monitored objectively via app-recorded session timestamps. The waitlist control group wore the Ōura Ring and completed all questionnaires identically without receiving any intervention. All participants wore an Ōura Ring Gen 3 throughout the study to objectively and continuously measure sleep architecture, sleep efficiency, and heart rate variability (HRV). Self-report questionnaires on perceived stress (Perceived Stress Scale; PSS-10), sleep quality (Pittsburgh Sleep Quality Index; PSQI), burnout (Copenhagen Burnout Inventory; CBI), and mindful attention (Mindful Attention Awareness Scale; MAAS) were administered before, immediately after, and four weeks after the 10-day intervention period. The study was conducted at the University of Southern Denmark, Odense, Denmark.
Interventions
BEHAVIORALApp-based mindfulness program (Headspace via Ōura app)
Participants completed one 10-minute guided audio mindfulness session daily ("destress" module, narrated by Headspace) delivered via the Ōura app for 10 consecutive days in free-living conditions at a time of their own choosing. Compliance was monitored objectively via app session timestamps.
Sponsors
University of Southern Denmark
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
BASIC_SCIENCE
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
20 Years to 60 Years
Healthy volunteers
Yes
Inclusion criteria
* Adults aged 20-60 years * Body mass index (BMI) in normal range (18.5-29.9 kg/m²) * Low stress at screening (Perceived Stress Scale (PSS-10) score ≤13) * Willingness to wear the Ōura Ring continuously throughout the study * No current regular mindfulness practice (defined as \>20 min/week) * Ability to provide written informed consent * Sufficient Danish or English language proficiency
Exclusion criteria
* Current regular mindfulness or meditation practice \>20 min/week * Self-reported diagnosis of cardiovascular or neurodegenerative disease * Current diagnosis of anxiety or depressive disorder * Use of psychotropic medications, hypnotics, or medications affecting heart rate variability (HRV) or sleep * Pregnancy * Shift work or highly irregular sleep schedules * Concurrent participation in another mindfulness or behavioral sleep intervention
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Sleep Efficiency | Pre-intervention (Time 0: 7-day average immediately before Day 1); post-intervention (Time 1: 7-day average immediately after Day 10); 4-week follow-up (Time 2: days 22-28 of follow-up) | Percentage of time asleep relative to total time in bed, measured continuously by Ōura Ring Gen 3 (accelerometry and photoplethysmography); computed as 7-day averages at each assessment timepoint. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Total Sleep Time | Pre-intervention (Time 0: 7-day average immediately before Day 1); post-intervention (Time 1: 7-day average immediately after Day 10); 4-week follow-up (Time 2: days 22-28 of follow-up) | Minutes asleep per night, measured by Ōura Ring Gen 3. |
| Deep Sleep Duration | Pre-intervention (Time 0: 7-day average immediately before Day 1); post-intervention (Time 1: 7-day average immediately after Day 10); 4-week follow-up (Time 2: days 22-28 of follow-up) | Minutes of slow-wave sleep per night, measured by Ōura Ring Gen 3. |
| Light Sleep Duration | Pre-intervention (Time 0: 7-day average immediately before Day 1); post-intervention (Time 1: 7-day average immediately after Day 10); 4-week follow-up (Time 2: days 22-28 of follow-up) | Minutes of non-rapid eye movement (NREM) light sleep per night, measured by Ōura Ring Gen 3. |
| Sleep Onset Time | Pre-intervention (Time 0: 7-day average immediately before Day 1); post-intervention (Time 1: 7-day average immediately after Day 10); 4-week follow-up (Time 2: days 22-28 of follow-up) | Clock time of sleep onset, measured by Ōura Ring Gen 3. |
| Heart Rate Variability (HRV) | Daily during 10-day intervention period | Root mean square of successive differences (RMSSD) (ms) measured during 10-min mindfulness sessions compared to an equivalent pre-session baseline period, assessed by Ōura Ring Gen 3. |
| Perceived Stress Scale (PSS-10) | Pre-intervention (Time 0: 7-day average immediately before Day 1); post-intervention (Time 1: 7-day average immediately after Day 10); 4-week follow-up (Time 2: days 22-28 of follow-up) | Perceived Stress Scale (PSS-10). Self-report questionnaire; sum score 0-40. |
| Pittsburgh Sleep Quality Index (PSQI) | Pre-intervention (Time 0: 7-day average immediately before Day 1); post-intervention (Time 1: 7-day average immediately after Day 10); 4-week follow-up (Time 2: days 22-28 of follow-up) | Pittsburgh Sleep Quality Index (PSQI). Self-report questionnaire; global score 0-21. |
| Copenhagen Burnout Inventory (CBI) | Pre-intervention (Time 0: 7-day average immediately before Day 1); post-intervention (Time 1: 7-day average immediately after Day 10); 4-week follow-up (Time 2: days 22-28 of follow-up) | Copenhagen Burnout Inventory (CBI). Self-report questionnaire; subscale scores 0-100%. |
| Mindful Attention Awareness Scale (MAAS) | Pre-intervention (Time 0: 7-day average immediately before Day 1); post-intervention (Time 1: 7-day average immediately after Day 10) | Mindful Attention Awareness Scale (MAAS). Self-report questionnaire; sum score 15-90. Administered to the mindfulness intervention group only. |
Countries
Denmark
Contacts
PRINCIPAL_INVESTIGATORUlrich Kirk, PhD
University of Southern Denmark
Outcome results
None listed