Table 1.
General characteristics of included studies.
| Category | First Author (Year Published) |
Including in Meta-Analysis | Heath Status of Subject |
Subjects Size (n) |
Age of Subject |
Protocol for Measurement | Measures | Main Outcome | Adverse Events | GRADE |
|---|---|---|---|---|---|---|---|---|---|---|
| Physiological health indicators | [10] Bang (2016) |
O | Healthy person | (Exp.) Urban forest walking (n = 18) (Con.) No intervention (n = 27) |
Adults (Male and female) |
Promised time | BP | [SBP] Exp. (123.50) and Con. (115.89) were not statistically different [DBP] Exp. (76.94) and Con. (72.44) were not statistically different |
NM | ⨁⨁◯◯ Low |
| [11] Brown (2014) |
O | Healthy person | (Exp1.) Urban forest walking (n = 27) (Exp. 2) Urban street walking (n = 27) (Con.) No intervention (n = 19) |
Adults (Male and female) |
On site (physiological data), online (psychological data) Following the 8-week intervention |
HR BP |
[SBP] Exp. 1 (129.3), Exp. 2 (129.7), and Con. (126.1) were not statistically different [DBP *] Exp. 1 (82.6), Exp. 2 (80.1) were higher than Con. (75.1) [HR-resting] Exp. 1 (68.3), Exp. 2 (65.1), and Con. (64.0) were not statistically different |
NM | ⨁⨁⨁◯ Moderate |
|
| [36] Calogiuri (2016) |
O | Healthy person | (Exp.) Nature exercise (n = 6) (Con.) Indoor exercise (n = 5) |
Adults (Male and female employee) |
After each session, between 8:00 and 9:00 AM (BP, saliva cortisol, blood cortisol) 15:00, 17:00, and 21:00 (blood cortisol) |
BP Cortisol (serum) |
[SBP] Exp. (119.99) and Con. (122.28) were not statistically different. [DBP *] Exp. (72.96) was lower than Con. (78.28). [Cortisol] Exp. (362.92) and Con. (343.78) were not statistically different. |
NM | ⨁⨁◯◯ Low |
|
| [37] Grazuleviciene (2016) |
X | Patient (CAD) |
(Exp.) Pine forest walking (n = 10) (Con.) Urban street walking (n = 10) |
Adults and elderly (45~75 years) (Male and female) |
Every day (7 days) 12:00~15:00. Before walking, At 1 min and 60 min after the initial exposure |
BP Cortisol (saliva) HR |
[DBP *] Exp. (−4.00) was lower than Con. (0.00) (change of baseline between day 1 and day 7) [DBP *] Exp. (−6.00) was lower than Con. (2.00) (change of 60 min after the walking between day 1 and day 7) |
NM | ⨁⨁⨁◯ Moderate |
|
| [15] Jia (2016) |
X | Patient (COPD) |
(Exp.) Forest walking (n = 10) (Con.) Urban walking (n = 8) |
Elderly (Male and female) |
Before breakfast the day after intervention | Cortisol | [Cortisol *] Exp. was lower than Con. † | NM | ⨁⨁◯◯ Low |
|
| [14] Mao(a) (2012) |
X | Patient (HTN) |
(Exp.) Forest walking (n = 12) (Con.) City walking (n = 12) |
Adult | Measured 30~40 min after intervention (physiological data), next evening (psychological data) |
BP HR |
[SBP *] Exp. was lower than Con. † [DBP *] Exp. was lower than Con. † [HR] Exp. and Con. were not statistically different † |
NM | ⨁⨁◯◯ Low |
|
| [23] Mao(b) (2012) |
X | Healthy person |
(Exp.) forest walking (n = 10) (Con.) city walking (n = 10) |
Adult (Male university students) |
Before breakfast (on the intervention day and the next day after 2 day intervention) | Cortisol | [Cortisol *] Exp. was lower than Con. † | NM | ⨁⨁◯◯ Low |
|
| [12] Niedermerier (2017) |
X | Healthy person |
Total = 42 (Exp 1.) Outdoor mountain hiking (n = NM) (Exp 2.) Indoor walking (n = NM) (Con.) No intervention (n = NM) |
Adult | NM | BP Cortisol HRV |
[SBP *] Exp.1 (121.3) and Con. (119.0) were higher than Exp. 2 (119.8) [DBP *] Exp 1. (78.3) and Con. (73.5) were higher than Exp. 2 (72.6) [Cortisol *] Exp. 1 (1.8) and Exp. 2 (1.8) were lower than Con. (2.3) [HRV-LF *] Exp.1 (2967) and Con. (2622) were higher than Exp. 2 (2614) [HRV-HF] Exp.1 (2409), Exp. 2 (1548), and Con. (1581) were not statistically different |
NM | ⨁⨁⨁◯ Moderate |
|
| [20] Song (2019) |
O | Healthy person |
(Exp.) forest walking (n = 72) (Con.) city walking (n = 72) |
Adult (Young female university students) |
5 min after intervention |
BP HRV HR |
[HF **] Exp. (105.12) was higher than Con. (57.11) [LF/HF **] Exp. (6.10) was lower than Con. (8.19). [HR **] Exp. (87.0) was lower than Con. (95.6) [SBP] Exp. (97.3) and Con. (97.5) were not statistically different. [DBP] Exp. (59.8) and Con. (59.2 mmHg) were not statistically different. [Pulse *] Exp. (69.3) was lower than Con. (71.9). |
NM | ⨁⨁◯◯ Low |
|
| [13] Wu (2020) |
X | Patient (HTN) |
(Exp.) Sit in forest (n = 20) (Con.) Sit in suburban (n = 11) |
Elderly | After intervention | BP HRV SPO2 |
[SBP] Exp. and Con. were not statistically different †. [DBP *] Exp. (67.95) was lower than Con. (71.64) [HRV-LF *] Exp. (35.0) was lower than Con. (50.88) [HRV-HF *] Exp. (60.54) was higher than Con. (48.37) [HRV-LF/HF *] Exp. (0.68) was lower than Con. (1.36) [SPO2 *] Exp. (98.1) was higher than Con. (97.55) |
NM | ⨁⨁⨁◯ Moderate |
|
| [38] Zeng (2020) |
X | Healthy person | (Exp. 1) Large species of cluster bamboo forest (n = 30) (Exp. 2) Bamboo sea site (n = 30) (Exp. 3) Bamboo park (n = 30) (Con.) Urban (n = 30) |
Adult | 15 min after intervention |
BP SPO2 |
[SPO2 *] Exp. 2 (97.47) after viewing was higher than before viewing (97.37) No statistical comparison between group (Exp. vs. Con.) |
NM | ⨁⨁◯◯ Low |
|
| [39] Lee (2011) |
O | Healthy person | (Exp.) Forest viewing (n = 24) (Con.) Urban viewing (n = 24) |
Adult (Male) |
35~90 min after intervention |
BP Cortisol HR HRV |
[LF/HF **] Exp. was lower than Con. † [SBP *] Exp. (116) was lower than Con. (118) [DBP] Exp. (54) was lower than Con. (56) [Cortisol] Exp. (0.34) and Con. (0.43) were not statistically different [HR *] Exp. (66.4) was lower than Con. (71.7) [HF **] Exp. was higher than Con. † |
NM | ⨁⨁⨁⨁ High |
|
| [40] Lee (2014) |
O | Healthy person | (Exp.) Forest walking (n = 24) (Con.) Urban walking (n = 24) |
Adult (Male) | 5 min after intervention |
BP HRV |
[LF/HF **] Exp. (1.5) was lower than Con. (1.9) [SBP] Exp. (114) and Con. (116) were not statistically different [HF **] Exp. (4.4) was higher than Con. (3.8) |
NM | ⨁⨁⨁⨁ High |
|
| Psychological health indicators |
[10] Bang (2016) |
O | Healthy person | (Exp.) Urban Forest walking (n = 18) (Con.) No intervention (n = 27) |
Adults (Male and female) |
Promised time | Depression (BDI) QOL |
[Depression] Exp. (5.11) and Con. (6.44) were not statistically different [QOL *] Exp. (23.94) was higher than Con. (20.70) |
NM | ⨁⨁◯◯ Low |
| [11] Brown (2014) |
X | Healthy person | (Exp1.) Urban forest walking (n = 27) (Exp2.) Urban street walking (n = 27) (Con.) No intervention (n = 19) |
Adults (Male and female) |
On-site (physiological data), online (psychological data) Following the 8 week intervention |
SF-8 general health SF-8 physical health SF-8 mental health |
[SF-8_general health] Exp. 1 (50.2), Exp. 2 (50.5), and Con. (47.8) were not statistically different [SF-8_physical health] Exp. 1 (54.9), Exp. 2 (51.8), and Con. (53.4) were not statistically different [SF-8_mental health] Exp. 1 (53.0), Exp. 2 (50.1), and Con. (47.4) were not statistically different |
NM | ⨁⨁⨁◯ Moderate |
|
| [21] Chun (2017) |
O | Patient (Chronic stroke) |
(Exp.) meditation walking and 5 sense experience in forest (n = 30) (Con.) meditation and walking in urban hotel (n = 29) |
Adults and elderly (36~79 years) (Male and female) |
Immediately before and after programs | Depression (BDI) Depression (HAM-D17) Anxiety (STAI) |
[BDI ***] Exp. was decreased (pre 14.2 vs. post 1.2) [BDI] Con. was not statistically different (pre 14.3 vs. post 14.0). [HAM-D17 ***] Exp. was decreased (pre 7.1 vs. post 1.6) [HAM-D17] Con. was not statistically different (pre 7.2 vs. post 7.1) [STAI ***] Exp. was decreased (pre 38.1 vs. post 27.6). [STAI ***] Con. was increased (pre 34.3 vs. post 44.4) |
NM | ⨁⨁⨁◯ Moderate |
|
| [22] Huber (2019) |
X | Patient (CLBP) |
(Exp 1) Green exercise (n = 27) (Exp 2) Green exercise and balneotherapy (n = 26) (Con) No intervention (n = 27) |
Adults (19~65 years) (Male and female) |
Day 1, after the intervention (day 8), after 4 months (day 120) | QOL (SF-36 total) QOL (SF-36 physical) QOL (SF-36 mental) QOL (WHO-5) |
Short-term effect (day 8) Exp. 1 was not changed. Exp. 2 was increased SF-36 total *, physical *, and WHO-5 ** † Long-term effect (day 120) All indices are not significant. † |
NM | ⨁⨁⨁◯ Moderate |
|
| [15] Jia (2016) |
X | Patient (COPD) |
(Exp.) Forest walking (n = 10) (Con.) Urban walking (n = 8) |
Elderly (Male and female) |
Before breakfast the day after intervention | Mood (POMS) | [Mood-T] Exp. was lower than Con.* † [Mood-D, Mood-A, Mood-V, Mood-F, and Mood-C] Exp. and Con. were not statistically different † |
NM | ⨁⨁◯◯ Low |
|
| [41] Mao (2017) |
X | Patient (CHF) |
(Exp.) Forest walking (n = 23) (Con.) City walking (n = 10) |
Elderly (65~85 years) (Male and female) |
5~10 min after intervention |
Mood (POMS) | [Mood-T *, Mood-D *, Mood-A *, and Mood-C *] Exp. was lower than Con. † | NM | ⨁⨁◯◯ Low |
|
| [14] Mao(a) (2012) |
X | Patient (HTN) |
(Exp.) Forest walking (n = 12) (Con.) City walking (n = 12) |
Adult | 30~40 min after intervention (physiological data), next evening (psychological data) |
Mood (POMS) | [Mood-T, Mood-V] Exp. and Con. Were not statistically different † [Mood-D *, Mood-A *, Mood-F *, and Mood-C *] Exp. was lower than Con. † |
NM | ⨁⨁◯◯ Low |
|
| [23] Mao(b) (2012) |
X | Healthy person | (Exp.) Forest walking (n = 10) (Con.) City walking (n = 10) |
Adult (Male) |
Before breakfast the day after intervention | Mood (POMS) | [Mood-T *, Mood-D *, Mood-A *, and Mood-F *] Exp. was lower than Con. † [Mood-V *] Exp. was higher than Con. † |
NM | ⨁⨁◯◯ Low |
|
| [19] Shin (2012) |
X | Patient (Alcoholic) |
(Exp.) Forest camping (n = 47) (Con.) Normal daily routine (n = 45) |
Adult | End day of the final session of the camp | Depression (BDI) | [Depression] Exp. (5.52) and Con. (15.36) were not statistically different | NM | ⨁⨁◯◯ Low |
|
| [20] Song (2019) |
O | Healthy person |
(Exp.) forest walking (n = 72) (Con.) city walking (n = 72) |
Adult (Young female) |
5 min after intervention |
Anxiety (STAI) Mood (POMS) |
[Total Mood **] Exp. (0.1) was lower than Con. (7.7) [STAI **] Exp. (34.8) was lower than Con. (45.3). |
NM | ⨁⨁◯◯ Low |
|
| [13] Wu (2020) |
O | Patient (HTN) |
(Exp.) Sit in forest (n = 20) (Con.) Sit in suburban (n = 11) |
Elderly | After intervention | Mood (POMS) | [Mood-T *] Exp. (12.90) was lower than Con. (15.55) [Mood-D *] Exp. (25.72) was lower than Con. (29.82) [Mood-A] Exp. and Con. were not significantly different † [Mood-V *] Exp. (26.90) was higher than Con. (24.36) [Mood-F *] Exp. (13.80) was lower than Con. (15.55) [Mood-C *] Exp. (13.75) was lower than Con. (16.64) |
NM | ⨁⨁⨁◯ Moderate |
|
| [40] Lee (2014) |
X | Healthy person | (Exp) Forest walking (n = 24) (Con) Urban walking (n = 24) |
Adult (Male) |
5 min after intervention |
Anxiety (STAI) Mood (POMS) |
[Mood-T **] Exp. (35.6) was lower than Con. (41.6) [Mood-A **] Exp. (37.7) was lower than Con. (39.0) [Mood-F **] Exp. (36.1) was lower than Con. (41.4) [Mood-C **] Exp. (42.2) was lower than Con. (44.3) [Mood-V **] Exp was higher than Con. † |
NM | ⨁⨁⨁⨁ High |
Note: † = No statistics; NM = Not mentioned; NS = Not significant; NA = Not available; BP = Blood Pressure; HR = Heart Rate; CAD = Coronary Artery Disease; COPD = Chronic Obstructive Pulmonary Disease; CLBP = Chronic Low Back Pain; CHF = Chronic Heart Failure; HTN = Hypertension; LF = Low Frequency (marker of cardiac parasympathetic control); HF = High Frequency (marker of cardiac sympathetic control); LF/HF = Low Frequency/High Frequency (index of sympathetic to parasympathetic autonomic activity); SPO2 = Saturation of Percutaneous Oxygen; BDI = Beck Depression Inventory; QOL = Quality of Life; SF-8 = 8-item Short Form health survey; HAM-D17 = 17-item version of the Hamilton Depression rating scale; STAI = Spielberger State-Trait Anxiety Inventory; SF-36 = 36-item Short Form health survey; WHO-5 = World Health Organization wellbeing index; POMS = Profile of Mood State, Mood-T = Mood-Tension anxiety, Mood-D = Mood-Depression dejection, Mood-A = Mood-Anger hostility, Mood-V = Mood-Vigor activity, Mood-F = Mood-Fatigue inertia, Mood-C = Mood-Confusion bewilderment. ⨁⨁⨁⨁ = high, ⨁⨁⨁◯ = moderate, ⨁⨁◯◯ = low, O = included, X = excluded, * = p < 0.05, ** = p < 0.01, *** = p < 0.001