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 World first: Massive thrombosis removed during early pregnancy
20.07.2017 | Universitätsspital Bern

nachricht Therapy of preterm birth in sight?
19.07.2017 | Universitätsspital Bern

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: Manipulating Electron Spins Without Loss of Information

Physicists have developed a new technique that uses electrical voltages to control the electron spin on a chip. The newly-developed method provides protection from spin decay, meaning that the contained information can be maintained and transmitted over comparatively large distances, as has been demonstrated by a team from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute. The results have been published in Physical Review X.

For several years, researchers have been trying to use the spin of an electron to store and transmit information. The spin of each electron is always coupled...

Im Focus: The proton precisely weighted

What is the mass of a proton? Scientists from Germany and Japan successfully did an important step towards the most exact knowledge of this fundamental constant. By means of precision measurements on a single proton, they could improve the precision by a factor of three and also correct the existing value.

To determine the mass of a single proton still more accurate – a group of physicists led by Klaus Blaum and Sven Sturm of the Max Planck Institute for Nuclear...

Im Focus: On the way to a biological alternative

A bacterial enzyme enables reactions that open up alternatives to key industrial chemical processes

The research team of Prof. Dr. Oliver Einsle at the University of Freiburg's Institute of Biochemistry has long been exploring the functioning of nitrogenase....

Im Focus: The 1 trillion tonne iceberg

Larsen C Ice Shelf rift finally breaks through

A one trillion tonne iceberg - one of the biggest ever recorded -- has calved away from the Larsen C Ice Shelf in Antarctica, after a rift in the ice,...

Im Focus: Laser-cooled ions contribute to better understanding of friction

Physics supports biology: Researchers from PTB have developed a model system to investigate friction phenomena with atomic precision

Friction: what you want from car brakes, otherwise rather a nuisance. In any case, it is useful to know as precisely as possible how friction phenomena arise –...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Closing the Sustainability Circle: Protection of Food with Biobased Materials

21.07.2017 | Event News

»We are bringing Additive Manufacturing to SMEs«

19.07.2017 | Event News

The technology with a feel for feelings

12.07.2017 | Event News

 
Latest News

NASA looks to solar eclipse to help understand Earth's energy system

21.07.2017 | Earth Sciences

Stanford researchers develop a new type of soft, growing robot

21.07.2017 | Power and Electrical Engineering

Vortex photons from electrons in circular motion

21.07.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>