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 Minimising risks of transplants
22.02.2018 | Friedrich-Alexander-Universität Erlangen-Nürnberg

nachricht FAU researchers demonstrate that an oxygen sensor in the body reduces inflammation
22.02.2018 | Friedrich-Alexander-Universität Erlangen-Nürnberg

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: Developing reliable quantum computers

International research team makes important step on the path to solving certification problems

Quantum computers may one day solve algorithmic problems which even the biggest supercomputers today can’t manage. But how do you test a quantum computer to...

Im Focus: In best circles: First integrated circuit from self-assembled polymer

For the first time, a team of researchers at the Max-Planck Institute (MPI) for Polymer Research in Mainz, Germany, has succeeded in making an integrated circuit (IC) from just a monolayer of a semiconducting polymer via a bottom-up, self-assembly approach.

In the self-assembly process, the semiconducting polymer arranges itself into an ordered monolayer in a transistor. The transistors are binary switches used...

Im Focus: Demonstration of a single molecule piezoelectric effect

Breakthrough provides a new concept of the design of molecular motors, sensors and electricity generators at nanoscale

Researchers from the Institute of Organic Chemistry and Biochemistry of the CAS (IOCB Prague), Institute of Physics of the CAS (IP CAS) and Palacký University...

Im Focus: Hybrid optics bring color imaging using ultrathin metalenses into focus

For photographers and scientists, lenses are lifesavers. They reflect and refract light, making possible the imaging systems that drive discovery through the microscope and preserve history through cameras.

But today's glass-based lenses are bulky and resist miniaturization. Next-generation technologies, such as ultrathin cameras or tiny microscopes, require...

Im Focus: Stem cell divisions in the adult brain seen for the first time

Scientists from the University of Zurich have succeeded for the first time in tracking individual stem cells and their neuronal progeny over months within the intact adult brain. This study sheds light on how new neurons are produced throughout life.

The generation of new nerve cells was once thought to taper off at the end of embryonic development. However, recent research has shown that the adult brain...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

2nd International Conference on High Temperature Shape Memory Alloys (HTSMAs)

15.02.2018 | Event News

Aachen DC Grid Summit 2018

13.02.2018 | Event News

How Global Climate Policy Can Learn from the Energy Transition

12.02.2018 | Event News

 
Latest News

Stiffness matters

22.02.2018 | Life Sciences

Magnetic field traces gas and dust swirling around supermassive black hole

22.02.2018 | Physics and Astronomy

First evidence of surprising ocean warming around Galápagos corals

22.02.2018 | Earth Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>