Indian Discussion Forum

As millions of Americans flock to the gym armed with New Year's resolutions to get in shape, medical experts are offering an additional reason to exercise: Regular workouts may help fight off colds and flu, reduce the risk of certain cancers and chronic diseases and slow the process of aging.

Physical activity has long been known to bestow such benefits as helping to maintain a healthy weight and reduce stress, not to mention tightening those abs. Now, a growing body of research is showing that regular exercise -- as simple as a brisk 30- to 45-minute walk five times a week -- can boost the body's immune system, increasing the circulation of natural killer cells that fight off viruses and bacteria. And exercise has been shown to improve the body's response to the influenza vaccine, making it more effective at keeping the virus at bay.

'No pill or nutritional supplement has the power of near-daily moderate activity in lowering the number of sick days people take,' says David Nieman, director of Appalachian State University's Human Performance Lab in Kannapolis, N.C. Dr. Nieman has conducted several randomized controlled studies showing that people who walked briskly for 45 minutes, five days a week over 12 to 15 weeks had fewer and less severe upper respiratory tract infections, such as colds and flu. These subjects reduced their number of sick days 25% to 50% compared with sedentary control subjects, he says.

Medical experts say inactivity poses as great a health risk as smoking, contributing to heart disease, diabetes, hypertension, cancer, depression, arthritis and osteoporosis. The Centers for Disease Control and Prevention says 36% of U.S. adults didn't engage in any leisure-time physical activity in 2008.

Even lean men and women who are inactive are at higher risk of death and disease. So while reducing obesity is an important goal, 'the better message would be to get everyone to walk 30 minutes a day' says Robert Sallis, co-director of sports medicine at Fontana Medical Center, a Southern California facility owned by managed-care giant Kaiser Permanente. 'We need to refocus the national message on physical activity, which can have a bigger impact on health than losing weight.'

Regular exercise has been shown to combat the ongoing damage done to cells, tissues and organs that underlies many chronic conditions. Indeed, studies have found that exercise can lower blood pressure, reduce bad cholesterol, and cut the incidence of Type 2 diabetes.

Building on that earlier research, scientific studies are now suggesting that exercise-induced changes in the body's immune system may protect against some forms of cancer.

Researchers are also investigating whether exercise can influence aging in the body. In particular, they are looking at whether exercise lengthens telomeres, the strands of DNA at the tips of chromosomes. When telomeres get too short, cells no longer can divide and they become inactive, a process associated with aging, cancer and a higher risk of death.

In a study published in November in Circulation, the medical journal of the American Heart Association, German researchers compared two groups of professional athletes (32 of whom were in their early 20s, and 25 who were middle-aged) with two groups (26 young and 21 middle-aged) who were healthy nonsmokers, but not regular exercisers. The athletes had significantly less erosion in telomeres than their more sedentary counterparts. The study concluded that physical activity has an anti-aging effect at the cellular level, suggesting exercise could prevent aging of the cardiovascular system.

The guidelines, developed by the Department of Health and Human Services and available online at health.gov/paguidelines, recommend that adults get at least two hours and 30 minutes weekly of moderate-intensity aerobic physical activity, or one hour and 15 minutes a week of vigorous-intensity aerobic exercise, or an equivalent combination of both. The guidelines also say that additional health benefits can be had from as much as doubling the minimum recommendation for aerobic exercise. Also recommended: muscle-strengthening activities two or more days per week, which protects against a decline in bone mass, especially that experienced by post-menopausal women.
http://forum.globaltimes.cn/forum/showt ... hp?t=14761

Exercise is certainly good for our body, A regular physical activity can improve your mood and the way you feel about yourself. Researchers also have found that exercise is likely to reduce depression and anxiety and help you to better manage stress.