[ti:Study: Resistance Exercise May Protect Bones in Overweight Elderly Adults][by:shang05.com][00:00.00]更多听力请访问shang05.com[00:01.16]What is the best form of exercise for older adults who are dieting?[00:08.32]Doctors do not yet know the answer.[00:11.52]But one study suggests that elderly dieters may be able to protect[00:18.40]against bone thinning by doing resistance exercise.[00:23.56]Medical experts often use body mass index, or BMI,[00:30.52]to measure obesity – the condition of being very overweight.[00:36.28]BMI compares a person's height and weight.[00:41.32]A BMI of around 30 or higher is considered obese.[00:48.24]Worldwide the number of obese people has nearly tripled since 1975,[00:55.72]notes the World Health Organization.[01:00.04]Obesity problems among older adults are difficult to deal with.[01:05.84]This is because weight loss efforts can create health problems,[01:11.16]such as an increased risk of bone thinning.[01:16.08]Thin bones are more likely to fracture, the study team noted.[01:21.64]Their findings appeared in The Journal of Bone and Mineral Research.[01:28.80]For the study, researchers randomly put 141 obese adults into one of four groups.[01:39.04]The first group had dieters who did only aerobic exercise.[01:45.80]The second group had dieters who only did resistance exercise.[01:52.92]The third had dieters who did both forms of exercise.[01:59.52]The final group, the control group, did not exercise or change their diet.[02:07.24]The subjects met with dieticians and did supervised workouts over 26 weeks.[02:15.04]The control group went to some classes to educate them about healthy eating.[02:22.40]All of the subjects in the study had a BMI of 30 or greater.[02:28.56]The average age was 70 years old.[02:33.36]In the exercise groups, subjects were given custom diets[02:38.48]that created a deficit of about 500 to 750 calories a day.[02:47.12]They also did supervised one-hour workouts three times a week.[02:54.16]The aerobic exercises included walking on an exercise machine,[03:00.00]riding a stationary bicycle, and stair climbing.[03:05.68]Resistance exercises included upper- and lower- body exercises using weight machines.[03:14.60]All of the exercisers also did some activities designed to improve balance and flexibility.[03:24.04]People in all three diet groups lost about 9% of their body weight during the study.[03:32.16]Members of the control group lost about 1% of their body weight.[03:37.92]At the end of the study, all of the participants had a decrease in bone density.[03:45.00]But bone density decreased less in the older adults who did resistance exercise.[03:54.16]Bone density also decreased less in those who did resistance exercise and aerobic workouts.[04:03.28]Doctor Dennis Villareal was the lead writer of a report on the study.[04:10.08]"When undergoing weight loss therapy," he said, elderly patients should use[04:16.20]"some resistance exercise to protect against bone loss."[04:21.56]"Resistance exercise should be at least moderate in intensity," Villareal added in an email.[04:30.28]"We do not know if less-intense exercise would be effective[04:35.56]in protecting against bone loss during weight loss."[04:40.72]Villareal is with the Baylor College of Medicine[04:44.88]and the Michael E. DeBakey VA Medical Center in Houston, Texas.[04:51.40]One limitation of the study is that researchers only followed the subjects for about six months.[05:00.52]That length of time is too brief to confirm whether one type of exercise[05:07.68]might be better than another for fall or bone fracture prevention, the report said.[05:15.44]Cynthia Brown is a doctor with the Integrative Center for Aging Research[05:21.76]at the University of Alabama at Birmingham.[05:26.60]"Based on this study, one would conclude that (for) an older adult[05:32.12]who is obese and trying to lose weight, the combination of aerobic and resistance exercise[05:40.68]will help the most to maintain their bone mineral density and their general physical fitness," she said by email.[05:49.76]"Older adults who are able should do muscle-strengthening exercises (resistance exercise) at least twice a week."[05:58.12]Brown was not involved in the study.[06:01.80]She also suggested that older adults with health issues[06:06.56]"make sure they understand how these conditions affect their ability to exercise."[06:13.64]She added that "all older adults should be as physically active as their abilities and conditions allow."[06:23.44]I'm John Russell. 更多听力请访问shang05.com