At least 3.9 million early deaths are being averted worldwide every year by people being physically active, according to a new study published in The Lancet Global Health today by researchers at the Universities of Cambridge and Edinburgh.
The team behind the study argue that too often we focus on the negative health consequences of poor levels of physical activity when we could be celebrating the achievements of physical activity.
"Research into lifestyle factors such as lack of physical activity, poor diet, drinking alcohol, and smoking, tends to focus on the harms these do to health," said Dr Paul Kelly from the Physical Activity for Health Research Centre at the University of Edinburgh. "This helps create a narrative to try and prevent and reduce these behaviours.
"We also believe there is value in trying to understand the benefits that 'healthy behaviours' confer in order to argue for maintaining and increasing them. Can we look instead at population activity levels and estimate the health benefits of all this activity to society?"
In their study, Dr Tessa Strain from the MRC Epidemiology Unit at the University of Cambridge and colleagues used a number known as the Prevented Fraction for the Population - in this case, the proportion of deaths that were prevented because people are physically active.
The team looked at previously published data for 168 countries, on the proportion of the population meeting World Health Organization global recommendation of at least 150 minutes of moderate-intensity aerobic activity throughout the week, or 75 minutes of vigorous-intensity activity, or an equivalent combination. The proportion of the population meeting the recommended amount of physical activity varied substantially between countries, from 33% for Kuwait, to 64% for the United Kingdom, to 94% for Mozambique.
By combining these data with estimates of the relative risk of dying early for active people compared to inactive people, the authors were able to estimate the proportion of premature deaths that were prevented because people are physically active.
They found that globally, due to physical activity the number of premature deaths was an average (median) of 15% lower than it would have been - 14% for women and 16% for men - equating to approximately 3.9 million lives saved per year.
Despite considerable variation in physical activity levels between countries, the positive contribution of physical activity was remarkably consistent across the globe, with a broad trend towards a greater proportion of premature deaths averted for low- and middle-income countries. In low income countries, an average of 18% of premature deaths were averted compared to 14% for high income countries.
In the USA, 140,200 early deaths were prevented annually and in the UK 26,600.
Health experts often frame the debate in terms of the number of early deaths due to lack of physical activity, estimating that 3.2 million die prematurely each year. But the researchers say that by showing how many deaths are averted, it might also be possible to frame the debate in a positive way and this could have benefits to advocacy, policy and population messaging.
"We're used to looking at the downsides of not getting enough activity - whether that's sports or a gym or just a brisk walk at lunchtime - but by focusing on the number of lives saved, we can tell a good news story of what is already being achieved," said Dr Strain. "It tells us how much good is being done and helps us say 'look how much benefit physical activity is already providing - let's make things even better by increasing physical activity levels further'.
"Although there's a risk of complacency - people asking why we need to invest more when it's already providing benefit - we hope our findings will encourage governments and local authorities to protect and maintain services in challenging economic climates."
The research was primarily funded by the Medical Research Council.
Six ways to keep active during lockdown
- Go out for a daily walk, wheel, or whatever movement you are able to do
- Go for a cycle ride or run if you're able to
- Do stretching exercises or yoga for your muscles and joints
- If you have a garden, do some gardening - great for stretching and bending
- Activity in greenspace or parks and activity with others may have additional mental and social health benefits
- Join an online exercise session
Strain, T. et al. Use of the prevented fraction for the population to determine deaths averted by existing prevalence of physical activity: a descriptive study. Lancet Glob Health 2020; 18 Jun 2020;
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About the University of Cambridge
The mission of the University of Cambridge is to contribute to society through the pursuit of education, learning and research at the highest international levels of excellence. To date, 109 affiliates of the University have won the Nobel Prize.
Founded in 1209, the University comprises 31 autonomous Colleges and 150 departments, faculties and institutions. Cambridge is a global university. Its 19,000 student body includes 3,700 international students from 120 countries. Cambridge researchers collaborate with colleagues worldwide, and the University has established larger-scale partnerships in Asia, Africa and America.
The University sits at the heart of the 'Cambridge cluster', which employs more than 61,000 people and has in excess of £15 billion in turnover generated annually by the 5,000 knowledge-intensive firms in and around the city. The city publishes 316 patents per 100,000 residents. http://www.cam.ac.uk
About the MRC Epidemiology Unit
The MRC Epidemiology Unit is a department at the University of Cambridge. It studies the genetic, developmental and environmental factors that cause obesity, type 2 diabetes and related metabolic disorders and the development and evaluation of strategies for the prevention of these diseases in the general population. http://www.mrc-epid.cam.ac.uk
About the Medical Research Council
The Medical Research Council is at the forefront of scientific discovery to improve human health. Founded in 1913 to tackle tuberculosis, the MRC now invests taxpayers' money in some of the best medical research in the world across every area of health. Thirty-three MRC-funded researchers have won Nobel prizes in a wide range of disciplines, and MRC scientists have been behind such diverse discoveries as vitamins, the structure of DNA and the link between smoking and cancer, as well as achievements such as pioneering the use of randomised controlled trials, the invention of MRI scanning, and the development of a group of antibodies used in the making of some of the most successful drugs ever developed.
Today, MRC-funded scientists tackle some of the greatest health problems facing humanity in the 21st century, from the rising tide of chronic diseases associated with ageing to the threats posed by rapidly mutating micro-organisms. The Medical Research Council is part of UK Research and Innovation. https://mrc.ukri.org/
The Lancet Global Health