Physical activity in natural environments, or 'green exercise', is estimated to provide health benefits of £2.2 billion a year to the English adult population, according to new research published in the journal Preventive Medicine.
Researchers from the University of Exeter Medical School and Public Health England analysed data from the world's largest study on recreational visits to natural places, such as parks, woods and beaches. They estimated that over 8 million adults in England engage in green exercise each week, resulting in over 1.3 billion green exercise visits a year.
Green exercise was defined in the study as nature-based activities of moderate to vigorous intensity and lasting over 30 minutes. Examples included dog walking, running, horse riding, outdoor swimming and mountain biking. Because physical activity needs to be regular and sustained to benefit health, the team focused on those who reported regularly meeting government guidelines for physical activity (i.e. 5 x 30 minutes each week). They then worked out what proportion of these people's weekly physical activity took place in natural settings and estimated the benefits to health associated with their levels of green exercise if sustained across the year.
Dr Mathew White, of the University of Exeter Medical School, is lead author of the research. He said: "We've known for a long time that regular physical activity is good for health and reduces the burden on health services. We have now worked out approximately how much physical activity regularly takes place in England's natural environments and how much this benefits adult health across the population. Ultimately these benefits will translate into savings for the NHS, highlighting the need to both maintain and promote our natural environments for exercise and health."
The data analysed was from Natural England's 'Monitor of Engagement with the Natural Environment' survey, which has over 280,000 participants and has been running for the last six years. The survey outcomes are part of England's official national statistics and people are sampled each week of the year, and in every region of the country, to reduce seasonal and geographical biases.
Two approaches to estimating health benefits were used, one exploring how many extra years in good health a person could expect to live from undertaking this level of exercise, and one exploring the number of lives saved each year from such activity. Because society is willing to invest resources in extending and saving lives, financial estimates of the monetary "value" of these benefits could be made.
Although the team recognises the need for caution in interpreting their results, for instance the survey relies on people accurately reporting instances of green exercise over the last week, they were reassured by finding very similar outcomes using two different approaches to analysing the data. Health economics expert at the University of Exeter Medical School, Associate Professor Anne Spencer, said: "Our estimates of the monetary value of potential health benefits are based on a number of assumptions so they need to be treated with care. However we used two different methods of analysing the data - one recommended by NICE (the National Institute of Health and Care Excellence) in England, and one developed by the World Health Organisation. We found similar results using both methods, which makes us more confident in our estimates. "
The research was conducted in collaboration with Public Health England as part of the Health Protection Research Unit in Environmental Change and Health. Dr Angie Bone, Head of Extreme Events at Public Health England, and co-author on the work, outlined some of the broader implications of the findings. She said: "Our parks, gardens, coasts and countryside play a vital role in improving health in this country, inspiring millions of us to get active outdoors every year. Evidence suggests that access to good quality green space is linked to feeling healthier, a lower body mass index and decreased levels of obesity, and improved mental health and wellbeing. This research highlights the positive impact getting outdoors has on our health, emphasising the importance of both promoting exercise outdoors to a wider population and maintaining the quality and accessibility of the nation's parks and wild places."
The study 'Recreational physical activity in natural environments and implications for health: A population based cross-sectional study in England' is published online in the journal Preventive Medicine.