Work Your Bones Now for Strength Later

Childhood exercise keeps leg bones and cartilage strong as adults

/ Author:  / Reviewed by: Robert Carlson, M.D

(RxWiki News) Sit ups for breakfast? Lazy bones as a child could make the body pay as a grown up. Adults may have greater knee cartilage and bone strength in their lower legs if they are more physically active as children.

Researchers have found that physical activity helps develop both leg muscle and core strength, which may be linked with bone density in the tibia as adults.

"This suggests physical activity in childhood can independently influence adult knee joint health possibly through adaptive mechanisms during growth," researchers said.

"Get out there and be active!"

The study, led by Graeme Jones, MD, PhD, professor of rheumatology and epidemiology at Menzies Research Institute in Tasmania, aimed to see if exercise and physical activity as children helps individuals have better cartilage in the knees and bone structure 25 years later.

The study included 298 participants from Australia. They ranged in age from 31- to 41-years-old and a little less than half were female. Using magnetic resonance imaging, researchers measured the amount of cartilage in participants' dominant knees and their tibia, one of the long bones in the lower leg.

In 1985, they surveyed participants on the amount of physical activity each child did, though researchers said more accurate information was revealed currently.

Physical work that equated to 170 beats per minute, as well as running both short and long distances, was linked to more bone and cartilage as adults.

Childhood strength in the hands, legs and core was also tied to an increase in bone as adults, but not for cartilage.

“The mechanism is uncertain, but I would contend that bone area gets larger to cope with the extra demands put on it by higher levels of physical activity, and then this lead to more cartilage, as cartilage covers the surface of bone,” Dr. Jones said in a press release.

The results were independent of any exercise the participants currently did as adults.

Although the findings add to the growing evidence of physical activity's importance, the authors note that bone and cartilage are still at risk of being damaged, which can lead to osteoarthritis.

“Physical activity is good, but if people have an injury while doing the physical activity, this is bad," Dr. Jones said.

"So injury prevention is important. Avoiding a high body mass index is also important, and physical activity will help with this.”

NHMRC of Australia funded the study, which will be presented November 13 at the American College of Rheumatology Annual Meeting in Washington, DC.

Reviewed by: 
Review Date: 
November 9, 2012
Last Updated:
May 23, 2013