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Friday 27 May 2016

Physical activity guidelines for adults


How much physical activity do adults aged 19-64 years old need to do to stay healthy?
To stay healthy or to improve health, adults need to do two types of physical activity each week: aerobic and strength exercises.
How much physical activity you need to do each week depends on your age. Click on the links below for the recommendations for other age groups:

Guidelines for adults aged 19-64

To stay healthy, adults aged 19-64 should try to be active daily and should do:
  • at least 150 minutes of moderate aerobic activity such as cycling or fast walking every week, and  
  • strength exercises on two or more days a week that work all the major muscles (legs, hips, back, abdomen, chest, shoulders and arms).  
  • 75 minutes of vigorous aerobic activity, such as running or a game of singles tennis every week, and
  • strength exercises on two or more days a week that work all the major muscles (legs, hips, back, abdomen, chest, shoulders and arms). 
  • A mix of moderate and vigorous aerobic activity every week. For example, two 30-minute runs plus 30 minutes of fast walking equates to 150 minutes of moderate aerobic activity, and
  • strength exercises on two or more days a week that work all the major muscles (legs, hips, back, abdomen, chest, shoulders and arms).  
A rule of thumb is that one minute of vigorous activity provides the same health benefits as two minutes of moderate activity.  
One way to do your recommended 150 minutes of weekly physical activity is to do 30 minutes on 5 days a week. 
All adults should also break up long periods of sitting with light activity. Find out why sitting is bad for your health.

What counts as moderate aerobic activity?

Examples of activities that require moderate effort for most people include:
  • walking fast
  • water aerobics
  • riding a bike on level ground or with few hills
  • doubles tennis
  • pushing a lawn mower
  • hiking
  • skateboarding
  • rollerblading
  • volleyball
  • basketball 
Moderate activity will raise your heart rate and make you breathe faster and feel warmer. One way to tell if you're working at a moderate level is if you can still talk, but you can't sing the words to a song.

What counts as vigorous activity?

There is good evidence that vigorous activity can bring health benefits over and above that of moderate activity.
Examples of activities that require vigorous effort for most people include:
Vigorous activity makes you breathe hard and fast. If you're working at this level, you won't be able to say more than a few words without pausing for breath.
In general, 75 minutes of vigorous activity can give similar health benefits to 150 minutes of moderate activity.
For a moderate to vigorous workout, try Couch to 5K, a nine-week running plan for beginners.

What activities strengthen muscles?

Muscle strength is necessary for:
  • all daily movement
  • to build and maintain strong bones
  • to regulate blood sugar and blood pressure
  • to help maintain a healthy weight
Muscle-strengthening exercises are counted in repetitions and sets. A repetition is one complete movement of an activity, like a bicep curl or a sit-up. A set is a group of repetitions.
For each strength exercise, try to do:
  • at least one set
  • eight to 12 repetitions in each set 
To get health benefits from strength exercises, you should do them to the point where you struggle to complete another repetition.
There are many ways you can strengthen your muscles, whether it's at home or in the gym. Examples of muscle-strengthening activities for most people include:
  • lifting weights
  • working with resistance bands
  • doing exercises that use your own body weight, such as push-ups and sit-ups
  • heavy gardening, such as digging and shovelling
  • yoga
Try Strength and Flex, a 5-week exercise plan for beginners to improve your strength and flexibility.
You can do activities that strengthen your muscles on the same day or on different days as your aerobic activity - whatever's best for you.
Muscle-strengthening exercises are not an aerobic activity, so you'll need to do them in addition to your 150 minutes of aerobic activity.
Some vigorous activities count as both an aerobic activity and a muscle-strengthening activity.
Examples include:
  • circuit training
  • aerobics
  • running
  • football
  • rugby
  • netball
  • hockey
For a summary on the health benefits of being more active, check out this Department of Health infographic (PDF, 500kb).
Page last reviewed: 11/07/2015
Next review due: 11/07/2017
reposted from:http://www.nhs.uk/Livewell/fitness/pages/physical-activity-guidelines-for-adults.aspx

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BMI categories may need adjusting, argue researchers

Wednesday May 11 2016
Improvements in treatments for weight-related conditions may have contributed towards the trend
There was a three-point upward shift in the 'optimal BMI' score
"Being overweight may not be as unhealthy as it was 40 years ago," BBC News reports.
New research has found a body mass index (BMI) of 27 is linked to the lowest rate of death – but someone with a BMI of 27 is currently classed as being overweight.
BMI is a score calculated by dividing your weight (usually in kilograms) by the square of your height (usually in metres and centimetres). Currently, a BMI of 25 to 29.9 is classified as being overweight.
Researchers looked at 120,528 people from Copenhagen, recruited from 1976 to 2013, and separately compared those recruited during the 1970s, 1990s and 2000s. They were followed up until they died, emigrated, or the study finished.
The BMI linked to the lowest risk of having died from any cause was 23.7 in the 1970s group, 24.6 in the 1990s group, and had further risen to 27 in the 2003-13 group.
It may be the case that the suggested upward shift in optimal BMI is the result of improvements in preventative treatments for weight-related conditions such as type 2 diabetes.
But this is just an estimate based on averages – it doesn't mean that having a "healthy" BMI is bad for you. Similarly, it shouldn't be assumed that it's now best to be in the overweight category. People often gain weight as they age, so there is the risk you could move from being overweight to obese.

Where did the story come from?

The study was carried out by researchers from Copenhagen University Hospital.
It was funded by the Danish Heart Foundation, the Danish Medical Research Council, Copenhagen County Foundation, Herlev and Gentofte Hospital, and Copenhagen University Hospital. 
The study was published in the peer-reviewed Journal of the American Medical Association (JAMA).
The study was covered by the UK media with a certain amount of glee, with the Daily Mail suggesting that the BMI system was a "blunt instrument".
It also said this study showed that, "Millions of Britons who are currently classed as overweight, actually have the optimal BMI and the lowest chance of death."
However, the study was reported on accurately, and the reports included expert views saying that people still need to keep an eye on their weight.

What kind of research was this?

This cohort study compared results from three large previous cohort studies in the same part of Denmark, starting at different times.
Researchers wanted to see if there had been a change over time in the optimal BMI score – that is, the BMI shared by people with the lowest rate of death from any cause.
While this type of study can show trends of this nature, it cannot explain why the changes happen.

What did the research involve?

Groups of adults in Copenhagen had their height and weight measured as part of three studies carried out in the city in 1976-78, then 1991-94, and the final study in 2003-13.
Researchers followed them up, then looked to see at which BMI people had the lowest chance of dying. They compared the numbers for the three studies to see if that number changed over time.
The first two studies were linked. Participants for the first study were invited back for a second round of measurements over the period from 1991-94, although younger people were recruited to add to the numbers. People in the third study had not taken part in either of the first two.
As well as weight and height, researchers checked whether people smoked, how much exercise they did, whether they'd been diagnosed with any medical conditions, including cancer or heart disease, and how much alcohol they drank.
They carried out sensitivity checks by including or excluding people with different risk factors to see whether any of them explained the overall results.
The researchers also looked at whether length of follow-up made a difference. They did this by carrying out their calculations with a much shorter follow-up period to see if the longer follow-up from the older studies distorted the results.

What were the basic results?

The average BMI at which fewest people in the studies died from any cause increased by three points over the three decades:
  • 23.7 (95% confidence interval [CI] 23.4 to 24.3) in 1976-78
  • 24.6 (95% CI 24 to 26.3) in 1991-94
  • 27 (95% CI 26.5 to 27.6) in 2003-13
The results showed a similar shift when researchers looked at just deaths from cardiovascular disease for non-smokers who had not been diagnosed with diabetes, cardiovascular disease or cancer, as well as for shorter periods of follow-up. None of the sensitivity analyses explained the trend.
In addition, researchers found the increased risk of death linked to being obese – a BMI of 30 or above – compared with a "healthy" BMI has gradually decreased to zero.
In the 1970s obese people had a 31% increased risk of death. By the 1990s it had reduced to a 13% increased risk, and by 2003-13 there was no longer a statistically significant link (adjusted hazard ratio 0.99, 95% CI 0.92 to 1.07).

How did the researchers interpret the results?

The researchers say their findings were "robust" and cannot be explained by confounding factors such as age, sex, smoking status and disease at the start of the study.
They said that, "If this finding is confirmed in other studies, it would indicate a need to revise the World Health Organization (WHO) categories presently used to define overweight."
They also said cohort studies cannot address the causes of the results, but speculated that their finding may reflect improvements in treatments for diseases affecting people with higher BMIs, such as heart disease and diabetes.
This would make it less risky to be overweight than in the 1970s, when more people died of these diseases. The reduction in smoking and increase in exercise they found could also have helped mitigate the effects of being overweight, they said.

Conclusion

The link between weight and health is not straightforward. We've known for years that if you plot death rates against BMI categories on a graph, you get a U-shaped curve, where people who are very underweight or very overweight are at higher risk of dying, while people in the middle have a lower risk.
This makes sense: extremes of weight are linked to illness, both as a cause or result. Many people with cancer or lung disease, for example, are underweight, which is one reason why lower BMIs are linked to higher death rates. That's why doctors talk about people having a "healthy" BMI.
What this study seems to show is that the lowest point of that U-shaped curve has shifted to the right, towards higher BMIs. But it doesn't mean that slimmer people are at a higher risk of death.
The study shows that in the period 2003-13, there was no difference between the death rates of people with a BMI of 18.5 to 24.9 (healthy) and those with a BMI of 25 to 29.9 (overweight), which were 4 per 1,000 per year for both groups.
The rate for obese people was 5 per 1,000 per year, despite this being a non-significant increased risk of death. There's certainly no need to try to put on weight if you are already at a healthy weight for your height.
The potential reasons for the shift are interesting. It may be, as the researchers suggest, that the diseases which killed more overweight people in the 1970s are now better treated and controlled, meaning that the risks of being overweight are smaller than they once were.
It's possible that the risks associated with being underweight have not decreased in the same way, which would automatically shift the "optimal" point towards overweight.
Also, despite a general increase in the population's BMI over the decades, health awareness has improved. Though the results have taken smoking status into account in the analyses, other factors, such as improvements in physical activity and alcohol moderation, could be having an influence.
However, this study has some limitations. Importantly, it was only carried out among white Danish people, which means it may not apply to other ethnic groups.
We know that some groups, such as people of south Asian origin, are more likely to have problems such as diabetes at lower BMIs than white people, so this study might not apply to everyone. And the follow-up for the most recent group studied was, on average, four years, so we don't yet know if this is a long-term trend.
The criticisms of the BMI system are not unfounded, though. BMI doesn't take into account the increased weight of muscle compared with fat – some athletes have high BMIs, despite being very fit, for example.
Waist circumference and waist-to-hip ratio can give a good indication of body "fatness". Regardless of your height or BMI, you should try to lose weight if your waist is:
  • 94cm (37in) or more for men
  • 80cm (31.5in) or more for women
You are at very high risk and should contact your GP if your waist is:
  • 102cm (40in) or more for men
  • 88cm (34in) or more for women
Read more about why waist size is important.
Analysis by Bazian. Edited by NHS ChoicesFollow NHS Choices on TwitterJoin the Healthy Evidence forum.
Analysis by Bazian
Edited by NHS Choices
reposted from: http://www.nhs.uk/news/2016/05May/Pages/BMI-categories-may-need-adjusting-argue-researchers.aspx

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Government reduces weekly target for mens alcohol consumption from 21 units to 14 units a week

New guidance puts male limit in line with women as chief medical officers warn that any amout of alcohol consumption increases cancer risk.

Men have been advised to drink no more than seven pints of beer a week – the same as the maximum limit for women – in the first new drinking guidelines to be released by the UK’s chief medical officers for 20 years.

They also advise there is no safe level of drinking for either sex, and issued a stark warning that any amount of alcohol consumption increases the risk of developing a range of cancers, particularly breast cancer.

Dame Sally Davies, the chief medical officer for England, said: “Drinking any level of alcohol regularly carries a health risk for anyone, but if men and women limit their intake to no more than 14 units a week it keeps the risk of illness like cancer and liver disease low.”

The new 14-unit recommended maximum is equivalent to a little more than nine small 125ml / 4.5 large 250ml glasses or a bottle and a half of wine; 14 single measures of spirits; seven pints of lager or beer. For women the limit is unchanged, but for men it drops from 21 units.

The UK’s recommended limit for men is now one of the lowest among countries that issue guidance for an appropriate intake of beer, wine and spirits and makes it one of only a handful of countries to issue identical advice for both sexes.

The 14-unit figure is based at a level expected to cause an overall lifetime risk of death due to alcohol of approximately 1%, according to the independent advisory group which formulated it. However, it cautioned that “there is little evidence regarding the impact of any guidelines in changing health behaviours”.

Prof Sir David Spiegelhalter, Winton Professor of the Public Understanding of Risk, University of Cambridge, said: “These guidelines define ‘low-risk’ drinking as giving you less than a 1% chance of dying from an alcohol-related condition. So should we feel OK about risks of this level? “An hour of TV watching a day, or a bacon sandwich a couple of times a week, is more dangerous to your long-term health. In contrast, an average driver faces much less than this lifetime risk from a car accident. It all seems to come down to what pleasure you get from moderate drinking.”

The latest Health Survey for England says that 85% of women and 68% of men drank 14 units or fewer a week in 2014, including those who did not drink at all. By comparison, 78% of men drank 21 units a week or fewer.

The guidance also recommends avoiding binge-drinking by spreading the 14 units over three or more days (to avoid drunken injuries as well as long-term illness) and says everyone should have “several” alcohol free days a week.

The guidance was published on the same day as the latest findings by the Committee on Carcinogenicity, which state that the risk of cancer increases with the more alcohol a person drinks. Even an intake of fewer than 10.5 units a week (or 1.5 a day) gives an increased risk of cancer of the mouth, throat and gullet and – in women – breast cancer.

The changes are based on evidence, unavailable in 1995 when the previous guidance was published, which also suggests the protective effect of alcohol against conditions such as ischaemic heart disease is weaker than previously believed.

Separately, an independent review of evidence, which formed the basis for the new advice, found that the benefits of alcohol for heart health only apply for women aged 55 and over and the greatest benefits is seen when they limit their intake to around five units a week, equivalent to around two standard glasses of wine.

reposted from: http://www.theguardian.com/society/2016/jan/08/mens-recommended-maximum-weekly-alcohol-units-cut-14

NHS: http://www.nhs.uk/news/2016/01January/Pages/New-alcohol-advice-issued.aspx

Government Guidelines: https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/489795/summary.pdf which says:
"This advice on regular drinking is based on the evidence that if people did drink at or above the low risk level advised, overall any protective effect from alcohol on deaths is overridden, and the risk of dying from an alcohol-related condition would be expected to be around, or a little under, 1% over a lifetime. This level of risk is comparable to risks from some other regular or routine activities, such as driving."