A brisk walk daily is the easiest way to trim waistline

Research from Duke University Medical Center shows that even a modest amount of brisk walking weekly is enough to trim waistlines and cut the risk of metabolic syndrome (MetS), an increasingly frequent condition linked to obesity and a sedentary lifestyle.

It’s estimated that about a quarter of all U.S. adults have MetS, a cluster of risk factors associated with greater likelihood of developing heart disease, diabetes and stroke: large waist circumference, high blood pressure, high levels of triglycerides, low amounts of HDL, or “good” cholesterol, and high blood sugar. To be diagnosed with MetS, patients must have at least three of these five risk factors, and according to many studies, a growing number of people do.

But Johanna Johnson, a clinical researcher at Duke Medical Center and the lead author of a new study examining the impact of exercise on MetS, said a person can lower risk of MetS by walking just 30 minutes a day, six days per week. “That’s about 11 miles per week. And our study shows that you’ll benefit even if you don’t make any dietary changes.”

“The results of our study underscore what we have known for a long time,” said Duke cardiologist William Kraus. “Some exercise is better than none; more exercise is generally better than less, and no exercise can be disastrous.”

The study appears in the December 15 issue of the American Journal of Cardiology.

The results come from a multi-year, federally funded study called STRRIDE (Studies of a Targeted Risk Reduction Intervention through Defined Exercise) that examined the effects of varying amounts and intensity of exercise on 171 middle-aged, overweight men and women.

Before exercising regularly, 41 percent of the participants met the criteria for MetS. At the end of the 8-month exercise program, only 27 percent did.

“That’s a significant decline in prevalence,” said Johnson. “It’s also encouraging news for sedentary, middle-aged adults who want to improve their health. It means they don’t have to go out running four or five days a week; they can get significant health benefits by simply walking around the neighborhood after dinner every night.”

Still, some exercise regimens were better than others. Those who exercised the least, walking about 11 miles per week, gained significant benefit, while those who exercised the most, jogging about 17 miles per week, gained slightly more benefit in terms of lowered MetS scores.

One group puzzled the researchers, however. Those who did a short period of very vigorous exercise didn’t improve their MetS scores as much as those who performed less intense exercise a longer period.

Kraus said there may be more value in doing moderate intensity exercise every day rather than more intense activity just a few days a week.

In all three of the study’s exercise groups, waistlines got smaller over the 8-month period. In general, men who exercised saw greater improvement in their MetS risk factors than women. But Johnson points out that at baseline, the men generally had worse scores than women, “so they had more room to improve,” she said.

Over the course of the STRRIDE study, the inactive control group – those who didn’t change their diet or activity level at all – gained an average of about one pound and a half-inch around the waist. “That may not sound like much, but that’s just six months,” Kraus said. “Over a decade, that’s an additional 20 pounds and 10 inches at the beltline.”

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Article adapted by MD Only Weblog from original press release.
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Contact: Michelle Gailiun
Duke University Medical Center

The study was funded by the National Institutes of Health.

Colleagues at Duke who contributed to the study include Cris Slentz, Gregory Samsa, Lori Bateman and Brian Duscha. Collaborating authors from East Carolina University include Joseph Houmard, Jennifer McCartney and Charles Tanner.

Diabetes is the leading cause of blindness among people aged 20-74 in Minnesota. Each year, according to the Minnesota Department of Health (MDH), between 400 and 700 Minnesotans go blind due to diabetes complications. Even when blood sugar is controlled, 60% of those having diabetes for more than 15 years will experience some form of diabetic eye disease in their lifetime.November is American Diabetes Month. This is a good time to schedule your annual dilated eye exam, urges the Minnesota Optometric Association (MOA), because type 2 diabetes can be caught early with this exam, and treated. MDH statistics show that of the 276,000 Minnesotans who have diabetes, 96,000 are unaware that they have it.

Currently, only eight in 10 Minnesotans with diabetes have a dilated eye exam every two years. “Most people do not realize that diabetics are twice as likely to suffer from cataracts, diabetic retinopathy and glaucoma. People may have these diseases before they are aware of it,” said Dr. Dirk Colby, president of the MOA and a doctor of optometry with West Metro Ophthalmology, Golden Valley and Plymouth, Minnesota. “It is critical for diabetic patients to come in every year,” said Dr. Colby. “Waiting two years or even worse, not coming in at all, can have a catastrophic effect.”

Diabetes is taking its toll on Americans and Minnesotans with eye diseases and type 2 diabetes is increasing rapidly due to the increase in obesity and decrease in exercise. These two risk factors are the leading causes of type 2 diabetes.

Diabetic retinopathy, the most common diabetic eye disease, is the leading cause of blindness in Minnesota, and overall in the United States. Diabetic retinopathy is caused by changes in the blood vessels of the retina. In some people with diabetic retinopathy, retinal blood vessels may swell and leak fluid; in others, abnormal new blood vessels grow on the surface of the retina. These changes may result in vision loss or blindness.

Cataracts occur when the normally clear lens in the eye becomes cloudy, impairing vision. Clouded vision may make it more difficult to read, drive, or see clearly. Glaucoma, an increase in fluid pressure inside the eye, leads to optic nerve damage and vision loss.

To help prevent diabetic eye diseases, the American Diabetes Association recommends people suffering from diabetes should:

• Keep your blood sugar under good control. People who keep their blood sugar levels closer to normal are less likely to have retinopathy.
• Bring high blood pressure down. High blood pressure can make eye problems worse.
• Get a dilated eye exam by a family eye doctor every year. Your optometrist will use drops to enlarge your pupils to look inside your eyes.

The Minnesota Optometric Association (MOA) recommends you see your family eye doctor right way if you have any of the following problems:

• Your vision is blurry.
• You see double, spots or floaters
• One or both eyes hurt
• You feel pressure in your eye
• You can’t see things at the periphery as well as before
• You have trouble reading

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Article adapted by MD Only Weblog from original press release.
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Contact:
Jim Meffort-Nelson
minnesota.aoa.org

How Exercise Stops Memory Loss

Research has shown that people who exercise do better on memory tests. Now a new Columbia University Medical Center study explains specifically what exercise does within the brain. Exercise, the researchers found, targets a region of the brain within the hippocampus, known as the dentate gyrus, which underlies normal age-related memory decline that begins around age 30 for most adults.

This finding is significant because it was accomplished via the first-ever observation of neurogenesis, the growth of neurons, within a living brain. Using an MRI imaging technique developed at Columbia, the researchers were able to identify neurogenesis within the dentate gyrus region following exercise. Previously, researchers were only able to prove neurogenesis upon postmortem exam in animal studies.

“No previous research has systematically examined the different regions of the hippocampus and identified which region is most affected by exercise,” said Scott A. Small, M.D., associate professor of neurology at Columbia University Medical Center and the study’s lead author. “I, like many physicians, already encourage my patients to get active and this adds yet another reason to the long list of reasons why exercise is good for overall health.”

Published in the March 12-16, 2007 early online edition of the Proceedings of the National Academy of Sciences, the finding builds upon previous research at Columbia that identified the role of the dentate gyrus region of the hippocampus in normal age-related memory decline. Additionally, Fred “Rusty” Gage, Ph.D. of the Salk Institute, a lead co-investigator on this study, had demonstrated in mice that the dentate gyrus is the one area of the brain where new neurons are generated, and that exercise improves this process. This is the first human study to emerge out of this observation.

“Our next step is to identify the exercise regimen that is most beneficial to improve cognition and reduce normal memory loss, so that physicians may be able to prescribe specific types of exercise to improve memory,” said Dr. Small, who is also a research scholar at the Columbia University Taub Institute for Research on Alzheimer’s Disease and the Aging Brain.

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Article adapted by MD Only Weblog from original press release.
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Contact: Elizabeth Streich, Columbia University Medical Center

Additional Columbia researchers who contributed to this study include: Ana C. Pereira, Rene Hen, Dan E. Huddleston, Adam M. Brickman, Alexander A. Sosunov, Guy M. McKhann, Truman R. Brown and Richard Sloan.

The Taub Institute for Research on Alzheimer’s Disease and the Aging Brain at Columbia University Medical Center is a multidisciplinary group that has forged links between researchers and clinicians to uncover the causes of Alzheimer’s, Parkinson’s and other age-related brain diseases and discover ways to prevent and cure these diseases. It has partnered with the Gertrude H. Sergievsky Center at Columbia University Medical Center which was established by an endowment in 1977 to focus on diseases of the nervous system. The Center integrates traditional epidemiology with genetic analysis and clinical investigation to explore all phases of diseases of the nervous system.

Columbia University Medical Center provides international leadership in basic, pre-clinical and clinical research, in medical and health sciences education, and in patient care. The medical center trains future leaders and includes the dedicated work of many physicians, scientists, nurses, dentists, and public health professionals at the College of Physicians & Surgeons, the College of Dental Medicine, the School of Nursing, the Mailman School of Public Health, the biomedical departments of the Graduate School of Arts and Sciences, and allied research centers and institutions.

Children not getting enough exercise

Less than three per cent of UK 11-year-olds are taking enough exercise, suggests research published ahead of print in the Archives of Disease in Childhood. It is recommended that kids spend at least an hour a day doing some form of moderate to vigorous physical activity, in a bid to promote good health and stave off the risks of subsequent obesity and diabetes.

The researchers monitored the physical activity levels of more than 5,500 11-year-olds in the south west of England over seven consecutive days between January 2003 and January 2005.

The children were part of the Avon Longitudinal Study of Parents and Children (ALSPAC), which has tracked the health of more than 14,000 children since birth.

Each child was kitted out with a special piece of equipment (accelerometer), worn on an elasticated belt, which recorded minute by minute the intensity and frequency of physical activity.

The researchers were particularly interested in total levels of physical activity and the amount of moderate to vigorous exercise the kids were taking daily.

When the data were analysed, they showed that the children were around twice as physically active as adults, but they were still not active enough.

Boys were more physically active than girls, and they were also more likely to engage in moderate to vigorous forms of activity.

One in five (22 per cent) girls averaged at least one bout of moderate to vigorous activity a day, lasting at least five minutes. This compares with 40 per cent of the boys.

But both sexes spent most of their day in light intensity activities. Less than one per cent of the children averaged at least one 20 minute bout a day.

And only just over five per cent of the boys and 0.4 per cent of the girls actually achieved current recommended daily levels of physical activity, equating to 2.5 per cent across both sexes.

Only sustained activity is likely to promote cardiorespiratory fitness, say the authors, adding: “It is a sobering thought that children’s activity levels actually peak at around this age [11] and decline precipitously during adolescence.”

Objective measurement of levels and patterns of physical activity, Online First Arch Dis Child 2007; doi: 10.1136/adc.2006.112136.

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Article adapted by MD Only Weblog from original press release.
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Contact Joanne Fryer

Universtiy Bristol University

Repeated sessions of exercise burn more fat than a single, long session

BETHESDA, Md. (July 10, 2007) — Taking a break in the middle of your workout may metabolize more fat than exercising without stopping, according to a recent study in Japan.  Researchers conducted the first known study to compare these two exercise methods—exercising continually in one long bout versus breaking up the same workout with a rest period.  The findings could change the way we approach exercise.  Who wouldn’t want to take a breather for that? 

“Many people believe prolonged exercise will be optimal in order to reduce body fat, but our study has shown that repetitions of shorter exercise may cause enhancements of fat mobilization and utilization during and after the exercise. These findings will be informative about the design of [future] exercise regimens,” said lead researcher Kazushige Goto, Ph.D. “Most people are reluctant to perform a single bout of prolonged exercise. The repeated exercise with shorter bouts of exercise will be a great help [in keeping up with fitness].”

This finding is part of a study entitled Enhancement of fat metabolism by repeated bouts of moderate endurance exercise, found in the June 2007 edition of the Journal of Applied Physiology, which is published by the American Physiological Society. It was conducted by Kazushige Goto, of both the Department of Life Sciences, Graduate School of Arts and Sciences, University of Tokyo, Komaba, Tokyo, Japan and the Institute of Sports Medicine, Bispebjerg Hospital, Copenhagen, Denmark; Naokata Ishii, of the Department of Life Sciences, Graduate School of Arts and Sciences, University of Tokyo, Komaba, Tokyo, Japan; and Ayuko Mizuno and Kaoru Takamatsu, both of the Institute of Health and Sport Sciences, University of Tsukuba, Tsukuba, Ibaraki, Japan. 

Summary of Methodology

The researchers used seven healthy (avg. body mass: 66.1, percentage fat: 17.6) men with an average age of 25 who were physically active and familiar with exercise and had them perform three separate trials:

• one single bout of 60-min exercise followed with a 60-min recovery period (Single)
  
• two bouts of 30-min exercise with a 20-min rest after the first 30-min bout, along with a 60-min recovery period at the end (Repeated)
  
• one 60-min rest period (Control)
  

The men performed each trial at the same time of day after fasting overnight.  They exercised on a single ergometer (cycling machine) at the commonly recommended exercise prescription of 60% maximum oxygen intake.  The recovery and rest periods were conducted while the subjects sat in chairs.   Blood samples were taken every 15 minutes during the exercise and every 30 minutes during the recovery period.  Their respiratory gas and heart rates were monitored continuously throughout the trial.

Summary of Results

The Repeated trial showed a greater amount of lipolysis (fat breakdown) than did the Single trial.  This Repeated trial also had a pronounced increase in free fatty acids and glycerol (chemical compounds that are released when stored fat is used) concentrations in the final 15 minutes of exercise, whereas these concentrations only progressively increased throughout the Single trial.  Also, the second half of the Repeated trial showed a significantly greater epinephrine response while also having a rapid decrease in insulin concentration as a result of lower plasma glucose.  This combination of high epinephrine and low insulin concentration may have also increased the lipolysis.  There was also enhanced fat oxidation in the recovery period of the Repeated trial than in the Single trial, but this result may be because the free fatty acids concentration was already high before the recovery period.

Conclusions

The American College of Sports Medicine recommends moderate exercise for the duration of 45 to 60 minutes to ensure a sufficient amount of energy is depleted in obese individuals.  This has caused a greater focus on extending exercise sessions in order to burn more fat.  However, this study shows that this method may not be the most effective way to enhance fat metabolism, as splitting up a long bout of exercise with a rest period burns more fat than a continuous bout of exercise.  This study could help with the practical application of implementing new exercise methods in order to better manage and control weight in individuals in the future.  However, Goto and his team of researchers plan on conducting further studies in order to explore the results in a variety of exercise durations as well as in different types of individuals.

SOURCE: Journal of Applied Physiology, June 2007

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Muscle Cramps: Don’t Let Them Cramp Your Workout

Almost every athlete complains about them, from professionals to the weekend warrior. Exercise-associated muscular cramps or (EAMC) are those sudden, involuntary, spasmodic and often very painful contractions of the muscle. A complete review of athletes muscle cramps appears in the July 2007 issue of the Journal of the American Academy of Orthopaedic Surgeons.

Lead author Javier Maquirrian, MD, from Buenos Aires, Argentina says the muscles more commonly affected by EAMC are:

– Calves and Feet
– Hamstrings
– Quadriceps
– Triceps

These muscles are already often contracted and in a shortened position during sports activities. Dr. Maquirrian stated that muscle cramps occur more during competition rather than in training, but delayed or nighttime cramps in fatigued athletes can also be attributed to exercise.

“There are some muscular cramps that develop in healthy people simply linked to certain circumstances or conditions such as exercise or pregnancy,” said Maquirrian. “However, muscle cramping (non-cerebral) that is sometimes inherited can also be a symptom of other underlying medical conditions like Parkinson’s disease, hypothyroidism and diabetes, as well as electrolyte disorders, metabolic or vascular disorder, nerve root damage, low serum magnesium levels or medication use, such as statins.”

Symptoms of athletic muscle cramps include:

– Explosive onset
– Acute pain
– Visible, palpable contractions presenting in one or more muscle
– Swelling
– Persistent soreness lasting two to three days

To help prevent muscle cramping, athletes should:

– Be well conditioned for the activity
– Avoid dehydration (drink plenty of fluids before, during and after athletic activity and exercise, especially in hot humid weather – sports drinks with electrolytes become more important in endurance type activities lasting over one hour)
– Do routine and periodic stretching, particularly of affected muscle groups;
– Maintain a well balanced diet (including electrolytes and carbohydrates) to avoid fatigue during the exercise
– Reduce the intensity and the duration of exercise if necessary

When athletes have recurring cramps, orthopaedic surgeons must rule out other muscle conditions including spasms, antalgic contracture (which causes a person to change position or gait to lessen pain and which may last several days), pain without contracture and painless contractures.

On occasion muscle biopsy or eletromyograms (EMGs) (which take recordings of the affected area) maybe necessary to discover the cause of cramping, including metabolic muscle disease. However, some rare genetic conditions, such as myalgia, often cannot even be detected with an EMG.

Athletes presenting severe or generalized cramps in muscles not subjected to exercise, or localized cramping together with confusion, altered state of consciousness or other signs of central nervous system involvement should receive immediate emergency medical attention. This will help rule out volume depletion, electrolyte imbalance, acute renal failure, intracranial disorders or other nervous system conditions.

Academy of Orthopaedic Surgeons

Cardiac Benefits of Sport

When asked about his personal recipe for old age, Winston Churchill used to answer: “First of all: No sports.” While being a visionary figure in world politics researchers in cardiovascular exercise science today would unanimously reply to his medical hypothesis: “Sorry, you are wrong.”

A large number of long-term observational studies clearly documented that increased levels of average daily physical activity were correlated to a reduced rate of coronary heart disease and reduced cardiac and all-cause mortality. Moderately active persons were 30-40% less likely to die from heart disease as compared to the inactive “couch potato.” Despite this solid epidemiologic evidence, the proportion of people who do not engage in sports at all is ever increasing: About two thirds of all Americans, for example, do not participate in regular leisure-time physical activity. This lack of sports is closely related to the epidemic of other risk factors for future heart attacks: Obesity, diabetes, high blood pressure, and elevated cholesterol levels. Together, these inactivity-related diseases cost about US$76 billion per year to treat in the US.

But physical activity is not only beneficial in healthy people to prevent cardiovascular diseases. Also patients with stable coronary artery disease can extend their life-expectancy by engaging in sports: A recent meta-analysis revealed a significant 27% reduction of total mortality among training patients and a significant 31% reduction in cardiac mortality. Even when compared to sophisticate interventional procedures, exercise training is surprisingly effective in improving the patient’s well-being. In a recent study which randomized patients with coronary 1- or 2-vessel disease to either the standard interventional treatment or to regular exercise training, we found a higher event-free survival in the training group and a similar improvement of cardiac symptoms. This finding confirms again that there is no cardiac gain without the pain of changing your inactive lifestyle.

But how does such a non-specific intervention as exercise training achieve these impressive results? Atherosclerosis – the chronic disease process finally leading to coronary narrowings and heart attacks – begins as a vascular malfunction before plaques develop.

Normally, a healthy vessel dilates and gets larger with increases of blood flow, which is especially important during activity to meet the increased demand for oxygen by the working muscles. In atherosclerosis, the artery loses its ability to dilate under these conditions, which leads to reduced blood supply during exercise. The key mediator which regulates vessel diameter is nitric oxide (NO), which is generated in endothelial cells by a special enzyme called �endothelial nitric oxide synthase� or eNOS. It has been found that NO production is reduced and NO degradation is increased in the early stages of heart disease – leading to endothelial dysfunction.

Exercise training and sports lead to repetitive increases in shear stress on the endothelium and can thereby stimulate the eNOS enzyme to produce more NO. Endothelial dysfunction is rare among active people and occurs later in life as compared to inactive individuals. In the last years we found that patients with stable coronary artery disease often have severe endothelial dysfunction, which can be dramatically improved by a four week training program – to an extent which is comparable with the effects of established medications such as lipid-lowering drugs (i.e. statins). This improvement of vessel dilation increases blood flow to the myocardium and thereby reduces clinical symptoms. In addition, endothelial dysfunction is regarded as the initial step toward atherosclerosis and plaque formation. By treating endothelial dysfunction with regular exercise training we can therefore retard the development of new coronary stenoses.

The key message emerging from these clinical studies is that sports and exercise – in addition to preventing obesity and diabetes – directly improve vascular function and reduce atherosclerosis. Considering that the majority of people do not engage in regular physical activities one can only say: The health of your heart is in your own hands. If you want to protect it: First of all, engage in regular sports activities!

Peer reviewed publication and references

Hambrecht R et al. Percutaneous coronary angioplasty compared with exercise training in patients with stable coronary artery disease: a randomized trial. Circulation. 2004;109(11):1371-8. Hambrecht R et al. Regular physical activity improves endothelial function in patients with coronary artery disease by increasing phosphorylation of endothelial nitric oxide synthase. Circulation. 2003;107(25):3152-8.

Hambrecht R et al. Effect of exercise on coronary endothelial function in patients with coronary artery disease. N Engl J Med. 2000;342(7):454-60.

Reference URL
escardio.org/vpo/ESC_congress_information

SOURCE: http://www.alphagalileo.org

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