What is the best dose of nature and green exercise for improving mental health? A multi-study analysis.

Year:
Benefits studied:
Uses studied: , , ,
States:
Place: 10 locations across the U.K.

Overview

Combining data from 10 U.K. studies, researchers demonstrated statistically significant improvements in self-esteem and mood after participants exercised outside in a natural setting. Although all cohorts and types of settings experienced improvements, the greatest gains are visible after short duration, light exercise, and among the mentally ill.

Relevance

This study is relevant for those who want to point to psychological research demonstrating the mental health benefits of exercise on trails in a variety of settings. Although this study uses accepted standardized measures of changes in mental health status, the actual numerical values may be difficult to place in context when communicating with those outside the mental health field.

Location

The study reviews 10 studies conducted across the U.K. in 10 locations.

Trail Type

The studies were not specifically on trails, but in five different settings: urban parks, farmland, forests, waterside, and wilderness. The types of activities include cycling, gardening, walking, fishing, boating, horseback riding, and sailing.

Purpose

The purpose of this study is to synthesize existing studies that measure the mental health effects of exercise in natural environments.

The authors are academic researchers. No specific funding source was cited.

Findings

  • Averaged across all studies, self-esteem and mood improved significantly after time spent exercising outside, across settings, exercise duration and intensity, and beginning health status.
  • The greatest change in mood and self-esteem occurred after five minutes spent outside, with smaller improvements up until half a day outside.
  • Self-esteem and mood increase across all levels of exercise intensity. The greatest gains in self-esteem are associated with light exercise and the greatest gains in mood come with either light or vigorous exercise (moderate exercise has the smallest gains).
  • Exercise near water is associated with the greatest increases in self-esteem and mood, although the findings between settings do not differ substantially.
  • Although individual study findings varied substantially, eight of 10 studies found a statistically significant increase in self-esteem and seven out of 10 studies found a statistically significant increase in mood after time spent exercising outside.
  • Men in general have somewhat larger gains than women in self-esteem and mood after exercising outside.
  • Those with mental illnesses have a greater increase in self-esteem and mood after exercising outside than those who are not mentally ill.

Methods

The authors identified 10 studies undertaken by the University of Essex that all used the same metrics to measure changes in mood after exercise in natural environments. All studies used the Rosenberg Self-Esteem Scale to measure self-esteem and the Profile of Mood States to measure changes in mood. Across all studies, participants were already enrolled in a program or visiting a site; therefore none of the studies can be considered randomized trials.

The authors compared mean scores for self-esteem and mood before and after exercise across all studies as well as by setting, duration, exercise intensity, age cohort, and mental health status.

Citation

Barton, J., and J. Pretty. 2010. “What is the best dose of nature and green exercise for improving mental health? A multi-study analysis.” Environmental Science and Technology 44(10): 3947-3955.