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It appears most of us sit too much. From Science Daily:

Obese Americans get less than one minute of vigorous activity per day, research shows

Researchers at the University of South Carolina’s Arnold School of Public Health have validated a new method for calculating physical activity, sedentary behavior, and the food energy requirements of Americans. The results suggest that as a nation, we spend more than 15 hours per day sleeping and sitting, and that obese men and women spend less than one minute per day in vigorous activity.

The study of the Physical Activity Ratio (PAR) protocol is significant because it provides the first nationally representative estimates of total daily energy expenditure, physical activity and sedentary behavior for the U.S. population.

Data sets for the study were obtained from the National Health and Nutrition Examination Survey 2005-2006, a complex sample of the U.S. population conducted by the Centers for Disease Control and Prevention, and included adults age 20 to 74. The sample population was then divided into three Body Mass Index (BMI) categories: normal weight (18-25 kg/m2), overweight (25-29.9 kg/m2) and obese (30 kg/m2 or more) and took into account all factors contributing to energy expenditure, including sleep, and the digestion and metabolism of food.

The study found that the 1,272 men and 1,325 women that comprised the final sample exhibited key differences based on sex and BMI. Men were taller, heavier, and had greater resting energy expenditure than women. Men also spent more hours per day engaging in moderate and vigorous physical activity, and reported less sleep.

Not surprisingly, obese men and women were significantly less physically active and spent more time in sedentary behaviors than their normal weight counterparts. Obese men and women also reported less sleep and spent almost no time in more intense forms of physical activity. “Given that physical inactivity is now a leading cause of death and disability in the world, these data are essential in advancing the science of obesity and health,” Archer said.

The following two articles discuss exercise and healthy aging. The first discusses Olga Kotelko and Bruce Grierson (author of the book "What Makes Olga Run").  From the Feb. 10, 2014 New York Times:

Seeking the Keys to Longevity in ‘What Makes Olga Run?’

No one would mistake Olga Kotelko for one of the Olympians competing in Sochi, Russia, but at age 94, she holds more world records than most: 26, to be exact, including age-group bests in the high jump, the hammer throw and the 200-meter run. Not bad for someone who took up track and field at age 77.

The result is this jolly book, which follows the pair as they consult researchers in fields like gerontology, exercise physiology and genetics for insights into Ms. Kotelko’s remarkable youthfulness.

What they find are countless opinions, but little definitive proof. Genes, diet, temperament, the theories abound. (Mr. Grierson rules out performance-enhancing drugs.) Or maybe it’s the exercise itself.

Research on twins suggests that heredity accounts for only about 25 percent to 30 percent of longevity, so it is not enough simply to label Ms. Kotelko a “genetic freak.” Besides, tests show she lacks at least one gene associated with longevity, and it turns out that her telomeres, chromosome caps that shorten with age, are merely average in length.

As for her diet, it is abundant and promiscuous. Her staples include red meat, sauerkraut, cottage cheese and sour milk, and she eats “immoderate amounts” of tapioca pudding. A centenarian friend of hers, the Australian shot-putter Ruth Frith, eschews vegetables altogether.

Among the potential anti-aging elixirs Mr. Grierson explores, exercise appears most potent. This old standby doesn’t just keep hearts pumping and muscles strong; studies suggest it may protect the mind too, by promoting the formation of neurons in the hippocampus — a part of the brain associated with memory.

Since she began her track and field career, Ms. Kotelko has rarely remained still, and that active lifestyle may be more important than her workouts at the track.

From the Feb. 7, 2014 Science Daily:

Exercise may slow progression of retinal degeneration

Moderate aerobic exercise helps to preserve the structure and function of nerve cells in the retina after damage, according to an animal study appearing February 12 in The Journal of Neuroscience. The findings suggest exercise may be able to slow the progression of retinal degenerative diseases.

Age-related macular degeneration, one of the leading causes of blindness in the elderly, is caused by the death of light-sensing nerve cells in the retina called photoreceptors. Although several studies in animals and humans point to the protective effects of exercise in neurodegenerative diseases or injury, less is known about how exercise affects vision.

Machelle Pardue, PhD, together with her colleagues Eric Lawson and Jeffrey H. Boatright, PhD, at the Atlanta VA Center for Visual and Neurocognitive Rehabilitation and Emory University, ran mice on a treadmill for two weeks before and after exposing the animals to bright light that causes retinal degeneration. The researchers found that treadmill training preserved photoreceptors and retinal cell function in the mice.

From the January 15, 2014 Science Daily:

Don’t Just Sit There! Prolonged Sitting Linked to Early Mortality in Women

Led by Cornell University nutritional scientist Rebecca Seguin, a new study of 93,000 postmenopausal American women found those with the highest amounts of sedentary time -- defined as sitting and resting, excluding sleeping -- died earlier than their most active peers. The association remained even when controlling for physical mobility and function, chronic disease status, demographic factors and overall fitness -- meaning that even habitual exercisers are at risk if they have high amounts of idle time.

Seguin and co-authors found that women with more than 11 hours of daily sedentary time faced a 12 percent increase in all-cause premature mortality compared with the most energetic group -- those with four hours or less of inactivity. The former group also upped their odds for death due to cardiovascular disease, coronary heart disease and cancer by 13, 27 and 21 percent, respectively.

The assumption has been that if you're fit and physically active, that will protect you, even if you spend a huge amount of time sitting each day," said Seguin, assistant professor of nutritional sciences in Cornell's College of Human Ecology. "In fact, in doing so you are far less protected from negative health effects of being sedentary than you realize."

The importance of 5 healthy behaviors in having the best chance of leading a disease free life. The 5 behaviors are: taking regular exercise, non-smoking, a low body weight, a healthy diet and a low alcohol intake. And as the researchers point out: "healthy behaviors have a far more beneficial effect than any medical treatment or preventative procedure".From Science Daily:

35 Year Study Finds Exercise Reduces Risk of Dementia

The study identifies five healthy behaviors as being integral to having the best chance of leading a disease-free lifestyle: taking regular exercise, non-smoking, a low body weight, a healthy diet and a low alcohol intake.

The people who consistently followed four or five of these behaviors experienced a 60 per cent decline in dementia and cognitive decline -- with exercise being the strongest mitigating factor -- as well as 70 per cent fewer instances of diabetes, heart disease and stroke, compared with people who followed none.

"The size of reduction in the instance of disease owing to these simple healthy steps has really amazed us and is of enormous importance in an aging population," said Principle Investigator Professor Peter Elwood from Cardiff University's School of Medicine. "What the research shows is that following a healthy lifestyle confers surprisingly large benefits to health -- healthy behaviors have a far more beneficial effect than any medical treatment or preventative procedure.

The Caerphilly Cohort Study recorded the healthy behaviors of 2,235 men aged 45-59 in Caerphilly, South Wales. 

 According to a new report, exercise can be as effective as many frequently prescribed drugs in treating some of the leading causes of death. This is a major finding! From the Dec.11, 2013 NY Times:

Exercise as Potent Medicine

For the study, which was published in October in BMJ, researchers compared how well various drugs and exercise succeed in reducing deaths among people who have been diagnosed with several common and serious conditions, including heart disease and diabetes.

They ended up with data covering 305 past experiments that, collectively, involved almost 340,000 participants, which is an impressive total. But most of the volunteers had received drugs. Only 57 of the experiments, involving 14,716 volunteers, had examined the impact of exercise as a treatment.The researchers compared mortality risks for people following any of the treatment options.

The results consistently showed that drugs and exercise produced almost exactly the same results. People with heart disease, for instance, who exercised but did not use commonly prescribed medications, including statins, angiotensin-converting-enzyme inhibitors or antiplatelet drugs, had the same risk of dying from — or surviving — heart disease as patients taking those drugs. Similarly, people with diabetes who exercised had the same relative risk of dying from the condition as those taking the most commonly prescribed drugs.

On the other hand, people who once had suffered a stroke had significantly less risk of dying from that condition if they exercised than if they used medications — although the study authors note that stroke patients who can exercise may have been unusually healthy to start with.

Only in chronic heart failure were drugs noticeably more effective than exercise. Diuretics staved off mortality better than did exercise.

Over all, Dr. Ioannidis said, “our results suggest that exercise can be quite potent” in treating heart disease and the other conditions, equaling the lifesaving benefits available from most of the commonly prescribed drugs, including statins.