Readers will be aware of my scepticism about telling people what not to do when it comes to health promotion. I’m much happier advising patients to do something new, an approach which emphasises the positive rather than the sometimes guilt-laden negative.
My gut feeling is that those who wish to lose weight often put too much emphasis on diet and not enough on exercise. So the recent research showing that just 20 minutes’ walking a day could cut the risk of premature death by almost a third was music to my ears.
The University of Cambridge researchers estimated that while some 337,000 early deaths in European men and women could be attributed to obesity, about twice this number could be blamed on inactivity. By increasing exercise levels even moderately, those who are obese could expect a 16 per cent reduced risk of dying early, while people of normal weight for their height and sex could benefit by 30 per cent.
Ulf Ekelund, who led the study, which was published in the American Journal of Clinical Nutrition, said: "This is a simple message: just a small amount of physical activity each day could have substantial health benefits for people who are physically inactive.
“Although we found just 20 minutes [of exercise] would make a difference, we should really be looking to do more than this – physical activity has many proven health benefits and should be an important part of our daily life.”
Recommended target
However, there is one significant disadvantage to their research which cannot be underestimated and that is for those who genuinely struggle to meet the recommended target of 150 minutes of moderate activity a week.
For many of us, not taking lifts to work and walking to and from the bus or train is not enough to rack up the 2½ hours suggested by government advisory bodies. And it’s even more disheartening for many older people who, because of mobility and other issues, find it hard to attain the 150-minute goal.
Which makes two reviews published some days ago in the BMJ even more welcome. A researcher at the University Hospital of Toulouse says studies show a dose-response relationship between physical activity and health. For example, a study of more than 250,000 US adults aged 50-71 found that less than one hour of moderate physical activity a week or 20 minutes or more of vigorous physical activity less than once a week was associated with a reduced risk of death from all causes.
Philipe de Souto Barreto believes that policies and actions to promote physical activity “should focus on people who are fully sedentary” and the main goal should be “to make small incremental increases in physical activities in their daily life rather than reaching current recommendations”.
Achieving target physical activity recommendations “should remain a goal but not the core public health message surrounding physical activity”, he writes.
In a second article, Prof Phillip Sparling and his colleagues at the Georgia Institute of Technology point out that older adults find it difficult to meet moderate and vigorous exercise targets.
They argue that focusing on the 150-minute recommendation “may mean that the benefits of lesser amounts of exercise are overlooked” and say a change in message to reduce sedentary time and increase light activities “may prove more realistic and pave the way to more intense exercise”.
Finally, a recent review in the British Journal of Sports Medicine shows the benefit of outdoor walking groups. Involving short group walks, they were found to be especially effective at increasing physical activity among older people. The review found that tailoring walking interventions to the needs of particular groups as well as targeting the most sedentary people in society produced the highest rates of participation.
It’s time to change the public health message: rather than feel bad the weeks you don’t manage 150 minutes, be positive about any 20 minutes of exercise you do get to do. mhouston@irishtimes.com muirishouston.com
