Nature-based Outdoor Activities for Promoting Stress Resilience in Employees

The goal of this randomized controlled trial (RCT) is to assess the impact of a nature-based workplace intervention on stress resilience in full-time employees in Hong Kong.

The main question it aims to answer is: Does a nature-based group activity intervention improve stress resilience in employees?

Researchers will compare the intervention group (participants who attend three nature-based group sessions) to the control group (participants who receive no intervention and continue their usual routines) to see if the nature-based activities lead to greater improvements in stress resilience compared to no intervention.

Participants will complete baseline measurements (questionnaires, blood pressure, and heart rate variability) one week before the first session.

If assigned to the intervention group: Attend three one-hour group sessions at a nearby park (once every two weeks, 8:00-9:00 AM) involving mindful walking, gentle movement, nature observation, breathing exercises, and group reflection

If assigned to the control group: Continue their usual daily routines with no specific activities

Complete follow-up assessments (same measurements as baseline): immediately after the second session and one week after the third session

Primary measurement: HRV Secondary measurements: Blood pressure, Perceived stress scale (PSS) and the Difficulties in emotion regulation scale (DERS).

Study Overview

• Status: Completed
• Conditions: Stress (Psychology)
• Intervention / Treatment: Behavioral: Nature outdoor activities

Detailed Description

Participants:

The participants of this study will be recruited from full-time employees at diverse corporate settings in Hong Kong. The sample size was determined using G*Power software. With a medium effect size (f = 0.25), an alpha level of 0.05, a desired power of 0.80, and a correlation among repeated measures of 0.50, the required total sample size was calculated to be 34. Accounting for an anticipated 20% attrition rate, the investigator aims to recruit 43 participants.

Study procedure:

This study uses a randomized controlled trial (RCT) to assess the impact of the workplace intervention on stress resilience in employees. To ensure allocation concealment, randomization will be performed by a third party (a program instructor who was not involved in participant recruitment or outcome assessment). Participants and researchers will be blinded to group assignment. The experimental procedure will be explained to potential participants in a recruitment poster, which required them to send their informed consent before participating. All participants will be invited to complete baseline measurements one week before the start of the first intervention session. Baseline measurements will take approximately 15-20 mins. Once the participants complete the questionnaire, the investigator will ask them to measure BP and HRV. All measurements will be taken after a 5-minute rest period in a seated position with back support, feet flat on the floor, and no talking. Participants will complete follow-up assessments at three time points using the same measures as at baseline (T1): T2 (immediately after the second session) and T3 (one week after the third session).

• Study Type: Interventional
• Enrollment (Actual): 160
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Hong Kong
  • Kowloon
    • Hong Kong, Kowloon, Hong Kong
      • The Hong Kong Polytechnic University

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Over 18 years
• Full-time employees

Exclusion Criteria:

• part-time employees
• individuals employed for less than six months
• those with symptoms of heart disease
• participants over 65 years of age

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Other
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Outdoor activity group; Three days outdoor activity group	Behavioral: Nature outdoor activities; After randomization, participants in the intervention group will attend three group activity sessions, while those in the control group will receive no intervention and were instructed to continue their usual daily routines. The group activity sessions will be conducted at a nearby park for one hour each session (8:00-9:00 AM). Sessions will be held once every two weeks, for a total of three sessions. Each session will be contained various group activities, such as mindful walking, gentle movement, nature observation, breathing exercises and group reflection. These group activities led by facilitators aims to increase social interaction and nature exposure. Participants in the control group were not asked to attend specific activities.
No Intervention: No-treatment control group; No specific activities required

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Heart rate variability (HRV)	HRV will be measured using SA-3000P (MEDICORE, Korea). The sensor is positioned with a strap around the fingertip of the middle finger on one of the participants hands. This study will use RMSSD (ms), SDNN (ms) and LF/HF ratio as HRV indicators to evaluate the stress response. In HRV analysis, higher RMSSD values indicate greater parasympathetic activity, reflecting relaxation and recovery. Similarly, Higher SDNN values indicate greater overall HRV, reflecting better autonomic nervous system flexibility. In contrast, higher LF/HF ratio values indicate sympathetic dominance, reflecting stress and arousal. This will be measured three times: at baseline (T1), immediately after the second session (T2), and one week after the third session (T3).	From enrollment to the end of treatment at 8 weeks

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Blood pressure (BP)	BP will be measured using a digital automatic BP monitor (PASESA AVE-2000, Japan) with an arm cuff placed on the non-dominant arm at heart level. Normal systolic blood pressure (SBP) is defined as 120-139 mmHg, and normal diastolic blood pressure (DBP) as 80-89 mmHg. The incidence of elevated BP (SBP ≥140 mmHg or DBP ≥90 mmHg) in follow-up, rather than the diagnosis of hypertension, will be used as an outcome indicator of changes in stress levels. This will be measured three times: at baseline (T1), immediately after the second session (T2), and one week after the third session (T3).	From enrollment to the end of treatment at 8 weeks
Perceived stress scale (PSS)	PSS measures the degree to which individuals perceive their lives as stressful. A total of 14 items (e.g., 'In the last three months, how often have you been upset because of something that happened unexpectedly? '), each of which uses a Likert scale ranging from 1 (never) to 5 (very often), are rated by participants. Higher score indicates higher stress levels. This will be measured three times: at baseline (T1), immediately after the second session (T2), and one week after the third session (T3).	From enrollment to the end of treatment at 8 weeks
Difficulties in emotion regulation scale (DERS)	DERS assesses emotion regulation problems. A total of 18 items (e.g., 'I have difficulty making sense out of my feelings') are rated by participants using a Likert scale ranging from 1 (almost never) to 5 (almost always). Higher scores indicate greater emotion regulation difficulties. This will be measured three times: at baseline (T1), immediately after the second session (T2), and one week after the third session (T3).	From enrollment to the end of treatment at 8 weeks

Collaborators and Investigators

• Sponsor: The Chinese University of Hong Kong, Shenzhen
• Investigators: Principal Investigator: Eun Yeong Choe, PhD, The Chinese University of Hong Kong, Shenzhen

Study record dates

Study Major Dates

• Study Start (Actual): September 30, 2025
• Primary Completion (Actual): October 30, 2025
• Study Completion (Actual): March 30, 2026

Study Registration Dates

• First Submitted: May 8, 2026
• First Submitted That Met QC Criteria: May 15, 2026
• First Posted (Actual): May 22, 2026

Study Record Updates

• Last Update Posted (Actual): May 22, 2026
• Last Update Submitted That Met QC Criteria: May 15, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Keywords: HRV; Nature-based outdoor activities
• Other Study ID Numbers: CUHKShenzhen_2

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No