Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Mild aerobic exercise no protection from osteoporosis

31.10.2002


Muscle strength, abdominal fat linked to bone mineral density



While day-to-day physical activities such as walking, housework and shopping may be good for your heart, they don’t do much for your bones, according to a Johns Hopkins study.
The new report, published in the November issue of the Journal of Internal Medicine, found that neither light-intensity activities nor aerobic fitness level contributed to bone health, contrasting previous studies suggesting that aerobics could play a role. Having a few extra pounds, however, was a help. Among a group of older adults studied, those with greater muscle strength and higher body fat, especially in the abdomen, had higher bone mineral densities.

"Carrying extra body weight increases the forces on bone, strengthening it, though the largest forces come from more vigorous exercise rather than routine low-intensity physical activity," says lead author Kerry J. Stewart, Ed.D., director of clinical exercise physiology at Hopkins. "In our study of typical older people, who unfortunately do not participate in regular vigorous exercise, daily activities and low-intensity exercise like walking appeared to be relatively ineffective for preventing aging-related bone loss."



Stewart does not advocate gaining weight to fight osteoporosis.

"Paradoxically, a high percentage of abdominal fat seems to increase bone mineral density," he says, "but it also increases the risk of heart disease, high blood pressure and diabetes, and worsens the symptoms of chronic conditions such as knee arthritis. Further research is needed to define methods that will reduce obesity while preserving or enhancing bone health."

Stewart and colleagues studied 84 adults (38 men and 46 women) ages 55 to 75 with higher than normal blood pressure but who were otherwise healthy. They were not exercising regularly, defined as moderate- or high-intensity exercise for 30 minutes a day, three or more times per week.

Researchers used X-rays to measure the participants’ bone mineral density in the total skeleton, lower spine and hip, and magnetic resonance imaging to calculate abdominal fat. They weighed each participant and had each do a treadmill exercise test and a series of weight-training exercises to measure aerobic fitness and muscle strength. In addition, the individuals completed a physical activity questionnaire.

Researchers found that aerobic exercise was not associated with bone mineral density but abdominal fat was. Muscle strength was associated with bone mineral density at some but not all sites.

Thirty percent of the women were taking estrogen and progesterone supplements. While such hormone replacement therapy has been known to positively benefit bone, in this study it contributed only modestly to bone mineral density and only at the lower spine.


The study was supported by the National Institutes of Health and the Johns Hopkins Bayview General Clinical Research Center. Co-authors were J.R. DeRegis; K.L. Turner, A.C. Bacher, J. Sung, P.S. Hees, M. Tayback and P. Ouyang.


Stewart, Kerry J., et al, "Fitness, fatness and activity as predictors of bone mineral density in older persons," Journal of Internal Medicine, Nov. 2002, Vol. 252, No. 5, pp. 1-8.

Karen Blum | EurekAlert!
Further information:
http://www.cardiology.hopkinsmedicine.org

More articles from Health and Medicine:

nachricht Collagen nanofibrils in mammalian tissues get stronger with exercise
14.12.2018 | University of Illinois College of Engineering

nachricht New discoveries predict ability to forecast dementia from single molecule
12.12.2018 | UT Southwestern Medical Center

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Data use draining your battery? Tiny device to speed up memory while also saving power

The more objects we make "smart," from watches to entire buildings, the greater the need for these devices to store and retrieve massive amounts of data quickly without consuming too much power.

Millions of new memory cells could be part of a computer chip and provide that speed and energy savings, thanks to the discovery of a previously unobserved...

Im Focus: An energy-efficient way to stay warm: Sew high-tech heating patches to your clothes

Personal patches could reduce energy waste in buildings, Rutgers-led study says

What if, instead of turning up the thermostat, you could warm up with high-tech, flexible patches sewn into your clothes - while significantly reducing your...

Im Focus: Lethal combination: Drug cocktail turns off the juice to cancer cells

A widely used diabetes medication combined with an antihypertensive drug specifically inhibits tumor growth – this was discovered by researchers from the University of Basel’s Biozentrum two years ago. In a follow-up study, recently published in “Cell Reports”, the scientists report that this drug cocktail induces cancer cell death by switching off their energy supply.

The widely used anti-diabetes drug metformin not only reduces blood sugar but also has an anti-cancer effect. However, the metformin dose commonly used in the...

Im Focus: New Foldable Drone Flies through Narrow Holes in Rescue Missions

A research team from the University of Zurich has developed a new drone that can retract its propeller arms in flight and make itself small to fit through narrow gaps and holes. This is particularly useful when searching for victims of natural disasters.

Inspecting a damaged building after an earthquake or during a fire is exactly the kind of job that human rescuers would like drones to do for them. A flying...

Im Focus: Topological material switched off and on for the first time

Key advance for future topological transistors

Over the last decade, there has been much excitement about the discovery, recognised by the Nobel Prize in Physics only two years ago, that there are two types...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

ICTM Conference 2019: Digitization emerges as an engineering trend for turbomachinery construction

12.12.2018 | Event News

New Plastics Economy Investor Forum - Meeting Point for Innovations

10.12.2018 | Event News

EGU 2019 meeting: Media registration now open

06.12.2018 | Event News

 
Latest News

Data use draining your battery? Tiny device to speed up memory while also saving power

14.12.2018 | Power and Electrical Engineering

Tangled magnetic fields power cosmic particle accelerators

14.12.2018 | Physics and Astronomy

In search of missing worlds, Hubble finds a fast evaporating exoplanet

14.12.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>