Exercise as it relates to Disease/'Green Exercise' - Outdoor Physical Activity's Effect on Depression

This is a critique of the journal article “Acute effects of outdoor physical activity on affect and psychological well-being in depressed patients – A preliminary study” by Frühauf, Niedermeier, Elliott, Ledochowski, Marksteiner, Kopp. (2016). Statement: this wiki factsheet has been created by u3097457.

What is the background to this research?
Mental health is a leading cause of healthcare system consultation, resulting in higher costs and burden on both sufferer and system. Depression is a mood/mental disorder affecting how individuals feel, think and cope with daily activities. Symptoms include; persistent sadness/anxiety, feeling hopeless/pessimistic, decreased energy/fatigue, difficulty concentrating, appetite changes, and potentially self-harm and/or suicide. Globally, depression affects around 350 million people, with this increasing. Physical Activity’s impact on depression has been thoroughly researched and considered an effective treatment. Additionally, time in outdoor natural environments can produce positive effects on physical and mental well-being, with ‘green exercise’ seen to reduce depression/depressive symptoms. With depression so prevalent, better understanding of outdoor exercise’s effects on depression could help provide cheaper, non-pharmacological treatments more cost effective and available than a gym membership.

Where is the research from?
Conducted at an undisclosed Austrian mental-health centre after University of Innsbruck ethics approval, the following institutions contributed; The article was published in Mental Health and Physical Activity, a Dutch publication with a growing reputation studying mental health and physical activity’s relationship. Elliot and Ledochowski have contributed to studies concerning physical activity, psychology and activity in outdoor/natural environments, whilst Kopp and Marksteiner are prolific researchers of physical activity, psychology and brain health. These research backgrounds provide the study credibility. No reported/known conflicts of interest bias this study’s findings, although being in Austria may have transferability implications for other countries and cultures.
 * University of Innsbruck, Dept. of Sport Science, Austria
 * Psychology Applied to Health Group, University of Exeter Medical School, United Kingdom
 * Department of Psychiatry and Psychotherapy A, Landeskrankenhaus Hall, Austria

What kind of research was this?
This study was a within-subjects experimental design. Experimental studies introduce treatments before observing results, ‘Within-Subject’ designs have all participants exposed to every treatment. This allows researchers to observe each conditions direct effect on each participant whilst reducing error variances from individual participant differences. Having outdoor and indoor conditions occur a week apart removed carryover effects, so benefits from one condition were not brought into the next. This study’s Repeated Measures ANOVA and Within-Subject design provide a good level of scientific evidence, but less than the Gold Standard systemic reviewed Randomised Controlled Trials.

What did the research involve?
14 day-unit in-patients with mild-moderate depression and no other acute illnesses (assessed by independent clinician) participated through to data analysis. Participants were assessed in 2 x 2 week periods (one in July, one in October 2014) involving data collection using; Beck Depression Inventory II, Feeling Scale, Felt Arousal Scale, and Mood Survey Scale. All participants performed three conditions within each two-week period. 60-minute group sessions were conducted with Feeling and Felt Arousal Scale questionnaires completed pre, post and every 15 minutes during conditions, and Mood Survey Scale completed pre and post condition. Outdoor and indoor conditions occurred at the same time of day, a week apart.

Table 2: Questionnaires and Measured Outcomes
One limitation concerns utilising two different exercise modes, questioning whether a difference in mode or location caused the observed results. This is mitigated as cycling and walking interventions have shown comparable effects on mood states. Additionally, 22 in-patients completed the study. But sickness, early release, incomplete questionnaires and different disease patterns reduced the sample size by over one third (36.4%). Had this not occurred, a larger sample size would have provided stronger results.

What were the basic results?
Feeling and Felt Arousal Scales showed higher effect sizes for affective valence and perceived activation from the Outdoor Condition over the Indoor Condition and significantly higher than Sedentary Controls after 60 minutes. Perceived activation was significantly higher in Outdoor Condition than Sedentary Control after 45 and 60 minutes and much higher than Indoor Condition between 30 and 45 minutes; Indoor Condition showed no significant changes. Mood Survey Scale showed Outdoor Condition had greater reductions in anger, depression and fatigue than Indoor Condition and Sedentary Control after 60 minutes.

How did the researchers interpret the results?
The researchers interpreted outdoor exercise is potentially more beneficial to depressive patients than indoor exercise, with both better than sedentary activities. The authors don’t over-emphasise their findings implications, rather remaining pragmatic. They accept some positives in favour of outdoor over indoor exercise, but outline the need for further research as this study’s size provides room for error.

What conclusions can we take from this research?
This study supports literature concerning outdoor exercise’s potentially greater benefit than indoor exercise at easing mild-moderately depressed individuals symptoms. With exercise and time in nature’s benefits on depression previously understood,     determining their combined effect on depression is worthwhile. With this study the first comparing outdoor vs indoor exercise’s effectiveness, the results look promising. However, larger sample sizes in future studies will strengthen these conclusions.

Practical advice
This research shows outdoor physical activity is more beneficial at aiding depression sufferers. It supports arguments for government investment in outdoor activity stations/parks/tracks/trails, which aid recreational exercise and are sustainable approaches to increasing population physical activity levels, with people visiting parks observed more likely to meet recommended activity guidelines. Outdoor activity provides a cost effective alternative for those in low income/socioeconomic circumstances. People looking to start exercising should always consult their doctor about any underlying/undiagnosed contraindications. Those concerned about depression should contact their doctor or a qualified mental health professional. Additionally, many organisations exist to help, please use them if needed.

Further information/resources
For further information on depression and exercise, including organisations to contact, please see links below.

Benefits of Outdoor Exercise Confirmed; Exercise and Depression; Depression and Exercise; Black Dog Institute; Beyond Blue; Headspace; Lifeline; Mental Health Council of Australia; Suicide Prevention Australia; World Health Organisation; National Institute of Mental Health