Charlyn Fargo, Contributor

The new exercise guidelines, released recently, haven't changed the basic message - you need to get moving to stay healthy. Adults gain substantial health benefits from two and a half hours a week of moderate aerobic physical activity and children benefit from one hour or more of physical activity a day, according to the new Physical Activity Guidelines for Americans. The comprehensive set of recommendations for people of all ages and physical conditions was released by the United States Department of Health and Human Services (HHS).

Guidelines

The new guidelines aim to end the confusion on how much exercise is needed and underscores that there are lots of ways to achieve a healthy level of exercise. The guidelines, considered as an exercise version of MyFood Pyramid, set a minimum sweat allotment for good health and, for most adults, that would be two and a half hours a week. In reality, how much physical activity you need depends largely on age and level of fitness.

Regular physical activity reduces the risk in adults of early death; coronary heart disease, stroke, high blood pressure, type 2 diabetes, colon and breast cancer, and depression, according to HHS. It can improve thinking ability in older adults and the ability to engage in activities needed for daily living. The recommended amount of physical activity in children and adolescents improves cardio-respiratory and muscular fitness as well as bone health, and contributes to favourable body composition.

The Physical Activity Guidelines for Americans are the most comprehensive of their kind and are based on the first thorough review of scientific research about physical activity and health in more than a decade. A 13-member advisory committee appointed in April 2007 by HHS secretary Michael O. Leavitt reviewed research and produced an extensive report.

In general, moderate exercise adds up for sluggish adults. Rake leaves, take a quick walk around the block or suit up for the neighbourhood softball game. More fit adults could pack in their week's requirement in 75 minutes with vigorous exercise, such as jogging, hiking uphill, a bike race or speedy laps in the pool. Children and teens need more - brisk activities for at least an hour a day, the guidelines say.

"It's important for all Americans to be active, and the guidelines are a road map to include physical activity in their daily routine," HHS Secretary Mike Leavitt said. "The evidence is clear - regular physical activity over months and years produces long-term health benefits and reduces the risk of many diseases. The more physically active you are, the more health benefits you gain."

For the full report, go to www.hhs.gov/news/press/2008pres/10/20081007a.html.

Letters

A winning question

Do soy-based foods lower blood cholesterol?

A: Although the Food and Drug Administration currently allows soy-based foods to feature health claims promoting their heart-health benefits, new research suggests that the link between soy and cholesterol is not as solid as scientists once thought.

A recent study tested the impact of 24 grams of soy protein a day on blood cholesterol and found no significant effect. (As a reference, 1 cup fortified soy milk provides about six to seven grams of soy protein, 0.5 cup tofu has roughly 10 grams and quarter cup roasted soy nuts about 11 grams.) Other recent studies have also suggested that we may not be able to count on the cholesterol-related benefits we'd once expected soy to deliver.

Effects of soy

However, soy's effects - specifically its role in lowering 'bad' LDL cholesterol - could be greater in people with more severe cholesterol elevations. Effects may also depend on what type of soy foods are chosen, which foods soy replaces and which foods continue to be eaten that may accentuate soy's benefits.

Unprocessed soy foods like tofu, edamame, soy milk and soy nuts certainly still have a place in a heart-healthy, cholesterol-lowering diet. These choices are a great replacement for fatty meat, high-fat dairy products and snack foods high in trans fat - key protagonists in raising blood cholesterol. Just don't expect to simply add soy foods to an unhealthy diet and benefit.

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