A Digital Mindfulness Intervention to Improve Sleep Efficiency and Heart Rate Variability in Healthy Adults

NCT07469644 | Completed

• 1 other identifier: 21345
• Study Type: interventional
• Target: 91
• Locations: 1 country
• Sites: 1

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.

Conditions

Sleep; Heart Rate

Keywords

Mindfulness; Sleep Efficiency; Heart Rate Variability

Outcome Measures

Primary Outcomes (1)

• Sleep Efficiency

  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.

  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)

Secondary Outcomes (9)

• 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)

• 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)

• 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)

• 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)

• Heart Rate Variability (HRV)

  Daily during 10-day intervention period

Study Arms (2)

Mindfulness Intervention

EXPERIMENTAL

Participants completed a 10-day app-based mindfulness program (one 10-min guided session/day via Ōura app) in free-living conditions.

Behavioral: App-based mindfulness program (Headspace via Ōura app)

Waitlist Control

NO INTERVENTION

Participants wore the Ōura Ring and completed all assessments without receiving any intervention.

Interventions

App-based mindfulness program (Headspace via Ōura app) BEHAVIORAL

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.

Mindfulness Intervention

Eligibility Criteria

• Age: 20 Years - 60 Years
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• 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

You may not qualify if:

• 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

Sponsors & Collaborators

• University of Southern Denmark: lead

Study Sites (1)

University of Southern Denmark. Department of Psychology.

Odense, 5230, Denmark

Location

Related Publications (1)

• Kirk U, Hovgaard CN, Persiani MTL, Romagnoli M, Staiano W. A digital mindfulness intervention improves sleep efficiency and heart rate variability in healthy adults. Sci Rep. 2026 Mar 21. doi: 10.1038/s41598-026-44902-w. Online ahead of print.

  PMID: 41862627 DERIVED

Study Officials

• Ulrich Kirk, PhD

  University of Southern Denmark

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: BASIC SCIENCE
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: March 3, 2026
• First Posted: March 13, 2026
• Study Start: December 1, 2023
• Primary Completion: May 1, 2024
• Study Completion: August 1, 2024
• Last Updated: March 13, 2026

Record last verified: 2026-03

Data Sharing

• IPD Sharing: Will share
• Shared Documents: STUDY PROTOCOL
• Time Frame: Following publication of primary results
• Access Criteria: Data available upon reasonable request to the corresponding author.

Locations

DK (1)