Research

Bone news: Everyday physical activity, such as walking and housework, are good for the heart, but they don't do much for bone strength, according to a new study from Johns Hopkins.

The report, published in the November issue of the Journal of Internal Medicine, found that neither light-intensity activity nor aerobic fitness contributed to bone health, contrary to previous studies.

Extra weight did help improve bone strength, says Dr. Kerry J. Stewart, lead author of the study - but the risks of heart disease, high blood pressure and diabetes are too great.

The study found that older adults with higher muscle strength and abdominal fat had stronger bones.

Vigorous exercise did help strengthen bones, but few older adults participate, says Dr. Stewart.

Hot news

Early bloomers: Boys and girls really are different, a Chicago researcher says: Girls who reach sexual maturity early are more likely to be obese, while the opposite is true for boys.

Dr. Youfa Wang, an assistant professor of human nutrition at the University of Illinois at Chicago, analyzed data on more than 3,000 boys and girls ages 8 to 14 from the Third National Health and Nutrition Examination Survey. Dr. Wang classified the children as "early maturers" if they reached a certain stage of sexual maturity earlier than their peers. Adjustments were made for age, residence, ethnicity, income, diet and physical activity.

In boys, early developers were found to be significantly taller but not heavier than other boys. Girls, however, were taller and heavier than peers who developed later.

The study suggests that, in boys, energy is dedicated to height, while in girls the extra energy is stored as fat tissue. More investigation is needed to find the causal relationship between sexual maturation and obesity.

Calendar

Registration: Sweat for a cause when the 93rd Thanksgiving Day 10K Race at 9 a.m. Nov. 28. The race, which starts and ends at Paul Brown Stadium downtown, benefits the Anthony Munoz Foundation, the Leukemia/Lymphoma Society and several other charitable organizations. Registration is available online, www.thanksgivingday

race.com, or brochures are available at Skyline Chili, Provident Bank, HoneyBaked Ham and the Running Spot.

Siting

Click: Check out www.xcskiworld.com for the scoop on cross-country skiing. The site includes tips to help beginners get in shape, news on the latest gear and a trip-planning feature.

Shelf Help

Forkfuls: The Hungry Gene: The Science of Fat and the Future of Thin (Atlantic Monthly Press; $25) by Ellen Ruppel Shell looks at the worldwide epidemic of obesity and the competition - economic and scientific - to find the cure.

Contact Peggy O'Farrell by phone, 768-8510; fax, 768-8330, or e-mail, pofarrell@enquirer.com