Benefits and harms of structured outdoor physical activity for people with somatic or mental diseases: A systematic review and meta-analysis.
Level 1 - systematic review of randomized trials
Systematic review and meta-analysis predominantly composed of randomized controlled trials (19 RCTs, 1 cohort study).
PubMed 38641081 · doi:10.1016/j.ypmed.2024.107966
What was done
A systematic review and random-effects meta-analysis was conducted across MEDLINE, EMBASE, CINAHL, CENTRAL, and Web of Science up to March 2023. Investigators evaluated randomized controlled trials and observational studies of structured outdoor physical activity compared to control conditions (no intervention, usual care, indoor physical activity, or outdoor activity without exercise) in adults with somatic or mental illnesses. Primary evaluated outcomes were health-related quality of life (HRQOL), physical function, pain, mental health outcomes, and adverse events, with evidence certainty appraised using GRADE.
What was found
The review included 20 studies (19 RCTs, 1 cohort study; n = 1759). At end of intervention, outdoor physical activity was associated with small improvements in HRQOL (k = 10, SMD = 0.45, 95% CI: 0.19 to 0.71) and physical function (k = 14, SMD = 0.39, 95% CI: 0.13 to 0.64), and moderate improvements in mental outcomes (k = 13, SMD = -0.52, 95% CI: -0.82 to -0.23). The effect on pain could not be determined. Four studies documented adverse events, encompassing non-serious events (falls, pain, fatigue) and serious events (hospitalization, pneumonia). Overall GRADE certainty across outcomes was very low.
Why it matters
These findings suggest that outdoor exercise interventions may provide broad functional and psychological benefits for individuals with chronic physical or mental health conditions, though current evidence is insufficient to guide clinical recommendations definitively.
Limits
The evidence base is constrained by very low GRADE certainty, substantial clinical heterogeneity in patient diagnoses and intervention modalities, small trial sample sizes, incomplete adverse event reporting across most trials, and an inability to draw conclusions regarding pain.
Cited by
- supports Studies comparing indoor versus outdoor exercise indicate that performing the same exercise outdoors produces greater health benefits.