Nature-based exercise therapies (surf or hike) reduce residual depression symptoms in service members with MDD, but sleep difficulties, low energy, and appetite changes commonly persist even among those who lose their diagnosis
In a secondary analysis of an RCT comparing weekly surf or hike therapy among 96 active duty service members with MDD, both interventions significantly improved depression symptoms. Among 88 completers, loss of MDD diagnosis reduced odds of most residual symptoms (ps ≤ .039), but sleep difficulties (56%), low energy (38%), and appetite changes (22%) remained common at postprogram even in those who lost diagnosis. Exercise type did not affect residual symptom odds.
This article is automatically generated from the structured evidence profile behind the claim above. Scores reflect the quality and quantity of available research, not clinical advice.
Nature-based exercise therapies (surf or hike) reduce residual depression symptoms in service members with MDD, but sleep difficulties, low energy, and appetite changes commonly persist even among those who lose their diagnosis The current body of evidence comprises 1 study, including 1 randomized controlled trial. EvidenceHub rates the overall confidence at 44/100 (low).
The Claim
Nature-based exercise therapies (surf or hike) reduce residual depression symptoms in service members with MDD, but sleep difficulties, low energy, and appetite changes commonly persist even among those who lose their diagnosis
This conclusion is most relevant to: Active duty U.S. service members with major depressive disorder (MDD), including a subgroup with comorbid PTSD (n=58, 66%).
What the Research Shows
The conclusion draws on 1 linked study. Highlights from the cited literature:
- ▸Residual depression symptoms following nature-based exercise therapies among U.S. service members. (Frontiers in physiology, 2026) —
How It Works
The proposed biological pathway:
- ▸Exercise therapy reduces overall depression severity
- ▸Loss of MDD diagnosis reduces odds of most residual symptoms
- ▸However, certain residual symptoms (sleep, energy, appetite) persist despite diagnosis loss
- ▸Result: Additional strategies targeting these transdiagnostic residual symptoms may be needed
Who Might Benefit
Evidence fit by population:
- ▸Active duty U.S. service members with major depressive disorder (MDD), including a subgroup with comorbid PTSD (n=58, 66%)
Recommended Dose
Weekly sessions (frequency not specified; likely 1x/week for 8 weeks)
Limitations & Caveats
Important context when interpreting this evidence:
- ▸Secondary analysis of an RCT, not designed to test residual symptom differences
- ▸No control group (both arms were active exercise interventions)
- ▸Residual symptom assessment based on single-item measures from a depression scale, not validated for individual symptom tracking
Frequently Asked Questions
What residual depression symptoms are most common after nature-based exercise therapy?▼
Sleep difficulties (56%), low energy (38%), and appetite changes (22%) were most common at postprogram among those who lost their MDD diagnosis.
Does the type of exercise (surf vs. hike) affect residual symptoms?▼
No, exercise therapy type was not related to the odds of any individual residual symptom (ps ≥ .225).
Does losing the MDD diagnosis reduce all residual symptoms?▼
Loss of diagnosis reduced odds of most residual symptoms (ps ≤ .039), but not suicidal ideation at 3-month follow-up (p = .088).
Are residual symptoms similar in those with comorbid PTSD?▼
Yes, similar patterns were seen, with sleep disturbance persisting in 42% of those who lost their PTSD diagnosis.
References
- 1.Otis NP, Glassman LH, Kline AC, Kobayashi Elliott KT, Michalewicz-Kragh B, Walter KH. “Residual depression symptoms following nature-based exercise therapies among U.S. service members..” Frontiers in physiology, 2026. PMID: 42548550 DOI: 10.3389/fphys.2026.1788999