2006年VOA标准英语-Elderly Life Expectancy Linked to Daily Physica（在线收听）

By David McAlary
Washington
11 July 2006

Former dancer Ann Smith leads a stretch class at Munson Community Health Clinic in Traverse City   
  
New medical research shows that elderly people can prolong their lives without vigorous exercise.  The study of people in their seventies and early eighties shows that consistent performance of usual daily activities such as stair climbing is associated with a much lower risk of death.

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Naomi Glass, 75, is retired, but that does not mean she is inactive.

"I never have a day where I have to think about how I am going to fill it," she said.  "It is always filled with something or other."

Between her housework and her busy schedule volunteering with various organizations, Naomi is often in motion.  A new study in the Journal of the American Medical Association says she may be prolonging her life.  It shows that the more active an elderly person is, the longer he or she may live.

"The thing about this study is, we measured usual daily activity and not traditional exercise," said Dr. Todd Manini at the National Institute on Aging near Washington. 

Dr. Manini and his colleagues collaborated with researchers at several other institutions across the United States to look at about 300 adults aged 70 to 82 who lived independently.  They wanted to see if their typical daily energy use was related to longer life.

Dr. Manini says the researchers gauged energy expenditure by measuring how much carbon dioxide the study participants expelled.

"The first thing you need to know is that anytime we use energy, it is released from the body as carbon dioxide," he explained.

Manini's team gave the elderly men and women special water to drink.  This made it possible to measure carbon dioxide in their urine.

"We found that over an eight-year period, that older adults in the low activity group had three times greater risk of death when compared to older adults in the high-activity group," he added.

People in the high-activity group tended to climb two more flights of stairs a day than those in the low-activity group.  They were also more likely to work for pay versus volunteering or not working at all.  Manini sums it up this way.

"The message here is that for older adults, any movement is better than no movement, and that this can come from usual daily activities," he said.

An editorial accompanying the study notes that higher levels of activity do appear to protect health.  But the writers, exercise physiologists Steven Blair of the Cooper Institute in Texas and William Haskell of Stanford University in California, say the Manini study's unique measurement of carbon dioxide expenditure does not document the intensity of the elderly people's activity.

They argue that the study's conclusions must be verified by more research.  Blair and Cooper say if they are, they could have a major implications for exercise recommendations.