Wednesday, January 15, 2014

Can exercising for just 60 seconds a week transform your health? The BBC's Dr Michael Mosley says 'fast exercise' is even more powerful than experts thought

No evidence is offered for the assertions below.  Diet and lifestyle generally have little impact on longevity.  See here for instance.  It is often asserted that something in the life of long-lived groups is responsible for the longevity but that is mere speculation. 

Genes are the key.  Nearly half of males die in or before their 60s.  I am still travelling well at age 70, despite living an extremely sedentary life and eating all the "wrong" foods.  But there were a lot of nonagenarians in my forebears

The men in my family are not long-lived. My grandfather died in his early 60s (though the fact that he was a Japanese prisoner in Burma during World War II can't have helped), while my father passed away at the relatively early age of 74.

When he died, he was on a dozen medicines and suffering from a range of diseases, including type 2 diabetes, heart failure, prostate cancer and what I suspect was early dementia.

At his funeral, a number of his friends commented on how similar I am to him. This was both flattering and disturbing, because I fear, along with his prominent nose, that I've inherited many of his more unhealthy tendencies.

But I also believe that although genes play a significant role in how well we age, lifestyle is just as important.

Down the centuries there have been lots of anti-ageing therapies, from injecting monkey glands to  mega-doses of vitamins. But only a few things have consistently been shown to influence how well we age.

These include not smoking, moderate drinking, eating a diet rich in fruit and vegetables, doing exercise and keeping your weight down.

I've never been a smoker or a heavy drinker and I like fruit and vegetables, so that's not a challenge. But when it comes to doing more exercise and staying slim, well, that has been far trickier.

I found the standard advice - eat less and be more active - largely ineffectual. I kept trying and failing.

Then, a couple of years ago, I began looking into a radically different approach to exercise called High Intensity Training (HIT). The idea is that instead of trying to shed weight and get healthier by jogging for hours, you can get many of the more important benefits of exercise from as little as three minutes of HIT a week.

Everyone agrees that getting more active will add years to your life (around 2.2 years, to be exact).  But, more importantly, it will significantly reduce your risk of developing a range of chronic diseases, from cancer to heart failure, dementia to diabetes.

Exercise will also help you sleep better, improve your mood and even perk up your sex life, according to the well-regarded Mayo clinic in the U.S.

But how much should you do? In 2008, a committee of U.S. scientists recommended 150 minutes of  moderate exercise a week, while cautioning the necessary amounts 'cannot yet be identified with a high degree of precision'.

This 150 minutes a week remains  the recommended level despite the fact that less than 20 per cent of us  do anything like that. The  most common excuse is a lack of time. That has certainly been mine - which is why the idea of HIT appeals to me.

The principles behind HIT are not new. In Fifties Britain, a young medical student called Roger Bannister was determined to become the first person in the world to run a sub-four-minute mile.
He didn't have lots of spare time for training so he would go down to the track and do interval sprints.  These consisted of running flat out for one minute, then jogging for two or three minutes before doing another one-minute sprint.

He would repeat this cycle ten times, then head back to work. The whole thing normally took less than 35 minutes.

In May 1954 he became the first person in the world to break the four-minute mile. Since then almost every middle-distance runner has done interval sprints as part of their training.

Jamie Timmons, professor of systems biology at Loughborough University, has spent many years researching the benefits of what has come to be known as HIT in normal people.

He assured me that three minutes of HIT a week have been shown to improve the body's ability to cope with sugar surges (i.e., your metabolic fitness), and how good the heart and lungs are at getting oxygen into the body (your aerobic fitness).

These two measures are great predictors of future health.


Poor children are more likely to be obese:  Study finds weight problems are creating a 'class divide'

I have been saying this for years

Childhood obesity really is creating a class divide, scientists have warned.

In the last decade the problem has started to decline in youngsters from middle class backgrounds while continuing to rise among those from poorer families.

The findings in the U.S. back British researchers who warned four years ago youngsters from less affluent and educated households will find themselves caught in the obesity trap.

Recent studies suggest rates have levelled off, but Professor Robert Putnam and colleagues say the overall trend masks a significant and growing difference between young people of upper and lower class.

The Harvard researchers say that low-income families are less likely to own a car.  This means they are prone to buying processed foods higher in fat and sugar with a long shelf-like.  Their neighbourhoods also have fewer playgrounds, pavements and recreational facilities.

Children of more educated parents, on the other hand, are more likely to eat breakfast and consume fewer calories from snacks.

Using data from two long-term national health surveys - the National Health and Nutrition Examination Survey and the National Survey of Children's Health - they showed obesity increased similarly for all 12 to 17 year-olds between 1988 and 2002.

Since then it has begun to decline among more well-off children, but has continued to rise among their less privileged counterparts, according to a report in Proceedings of the National Academy of Sciences.

Children from better backgrounds also had higher levels of physical activity and consumed fewer calories between 1999 and 2010 compared with the others.

The researchers said this could help explain the growing disparity in obesity among adolescents of different socio-economic status (SES).

Professor Putnam called for public interventions to promote healthy lifestyles among young people - particularly among those of lower SES.  He said: 'Socio-economic background influences an individual's food consumption and physical activity patterns. 'Not only are fresh vegetables and fruits costlier than fast food but healthy alternatives are sometimes hard to find in poor neighbourhoods.'

He added: 'Recent reports suggest the rapid growth in youth obesity seen in the 1980s and 1990s has plateaued.

'Although the overall obesity prevalence stabilised, this trend masks a growing socio-economic gradient.

'The prevalence of obesity among high socio-economic status adolescents has decreased in recent years, whereas the prevalence of obesity among their low socio-economic status peers has continued to increase.

'Additional analyses suggest socio-economic differences in the levels of physical activity - as well as differences in calorie intake - may have contributed to the growing obesity gradient.'

In December 2009 researchers at University College London said the numbers of obese children from manual class households were on course to considerably outnumber those from non-manual households.

They said: 'If trends continue as they have been between 1995 and 2007 in 2015 the number and prevalence of obese young people is projected to increase dramatically and these increases will affect lower social classes to a larger extent.'



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