Bicycle Network: Prevention
The power of physical activity to prevent disease
Strong medical evidence shows that the diseases caused by a sedentary lifestyle can be avoided, mitigated and remediated by moderate levels of physical activity.
Get on your bike - it might just save your life
A report just published in the prestigious medical journal The Lancet says a third of the world's adults are physically inactive and a sedentary lifestyle kills about 5 million people every year.
The report suggests inactivity is now killing as many people across the world as smoking and that the problem was now so bad it should be treated as a “pandemic”.
Researchers called for a global effort to promote physical exercise including bike riding by improving facilities on city roads and more physical education at schools.
"Roughly three of every 10 individuals aged 15 years or older - about 1.5 billion people - do not reach present physical activity recommendations," the report said.
The report said the picture for adolescents was worse than for adults with four out of five 13 to 15-year-olds not getting enough exercise.
The study defined inactivity as failing to do 30 minutes of moderate physical activity five times a week, 20 minutes of vigorous activity three times a week, or a combination of the two.
Researchers found that inactivity was more common in high-income countries, increases with age, is higher in women than in men. Addressing the issue would require fresh thinking, the report said, including ensuring the public was warned about the dangers of inactivity rather than just being reminded of the benefits of being active.
The research team, which included 33 researchers from around the world, said governments needed to look at ways to make physical activity more convenient, affordable and safer.
The team recommended adults do 150 minutes of moderate exercise, such as brisk bike riding, walking, or gardening, each week.
Reducing inactivity by 10 per cent could conservatively eliminate more than half a million deaths every year, the report said.
Researchers said the human body needed exercise to help organs, muscles and bones function optimally, but people were walking, running and cycling less and less as they spend more time in cars and in front of computers.
"The global challenge is clear - make physical activity a public health priority throughout the world to improve health and reduce the burden of disease," Pedro Hallal, one of the lead researchers, said.
The US Surgeon General's report
Many Americans may be surprised at the extent and strength of the evidence linking physical activity to numerous health improvements.
Most significantly, regular physical activity greatly reduces the risk of dying from coronary heart disease, the leading cause of death in the United States. Physical activity also reduces the risk of developing diabetes, hypertension, and colon cancer; enhances mental health; fosters healthy muscles, bones and joints; and helps maintain function and preserve independence in older adults.
Physical Activity and Health: A Report of the Surgeon General. 1996.
Getting Active 2002
Over the last decade there has been an increasing body of evidence supporting active lifestyles as one of the best investments for individual and community health...Engaging in regular physical activity, even of moderate intensity, reduces the risk of diseases such as cardiovascular disease, type II diabetes, osteoporosis, colon cancer, and obesity and injury. The benefits, however, go well beyond those of disease prevention. Regular physical activity has also been shown to facilitate better stress management, alleviate depression and anxiety, strengthen self-esteem, enhance mood and boost mental alertness. Additionally, it provides social benefits through increased social interaction and integration.
Among children and adolescents, regular physical activity and exercise has been associated with improved school performance, a greater sense of personal responsibility and group cooperation, and less drug and alcohol consumption.
...Physical inactivity is a serious public health problem that results in adverse health outcomes and greater health care costs. In addition to the need for lifestyle modification, it is now well recognised that there is an urgent need for environmental, social and policy changes to increase physical activity in the population.
Getting Australia Active 2002
The update in 2004
This review focuses on evidence for health gain among adults who are active, compared to those who are inactive. Areas covered include cardiovascular disease, diabetes, stroke, mental health, prevention of falls and obesity.
There have been several new studies on physical activity and all-cause mortality, which have replicated previous findings, and are consistent with Australian national physical activity recommendations.
One important Danish study in particular provided evidence that cycling to work reduces all-cause mortality risk, providing the first clear and positive evidence regarding active commuting.
...In summary, this review has further strengthened the epidemiological evidence-base for physical activity and health, with the most exciting new information in the diabetes prevention realm.
Getting Australia Active 2 Main section 2004
Getting Australia Active 2 Appendices 2004
Adults and Older People
In adults and older people there is good evidence to show that sufficient physical activity can:
- decrease the risk of premature death from cardiovascular disease, diabetes, colon and breast cancer;
- lower the risk of diabetes and prevent diabetes onset in people at risk;
- increase muscle and bone strength;
- prevent osteoporosis and reduce the risks and consequences of arthritis;
- prevent functional decline in middle aged and older people, especially through resistance training;
- improve health outcomes for people who are overweight or obese;
- assist people with established disease to manage their disease (eg lower high blood pressure and elevated lipid levels) and prevent further decline;
- prevent falls though the relative contributions of strength training, balance and gait training
- increase the ability of people with certain chronic, disabling conditions to perform activities of daily living.
There is mixed evidence in relation to the prevention of stroke and some cancers (eg lung,
prostate) as well as the role of physical activity in benefiting mental health.
Be Active 2005
Children and Young People
Although we know comparatively little about children’s levels of physical activity there is
sufficient evidence to show that it is insufficient compared with the national physical activity
recommendations for children and young people, and declining.4
In children and young people there is good evidence to show that physical activity can:
- have beneficial effects on adiposity and skeletal health;
- benefit psychological indicators including depression, self esteem, anxiety, stress and self concept
- have a positive correlation with behaviours such as not smoking.
For a more detailed summary of the evidence around physical activity and health, see
Appendix 1: Physical Activity and Specific Population Groups.
Be Active Australia A Framework for Health Sector Action for Physical Activity 2005–2010
These important documents were published by SIGPAH and the NPHP - see opposite