Those with low bone density should avoid crunches and sit-ups, experts say

SUNDAY, Oct. 8 (HealthSCOUT) -- From the impossibly well-toned trainers in exercise videos to the fitness buff next door, the advice is remarkably consistent: To flatten your tummy, do abdominal crunches and sit-ups.
　　Not so fast, say fitness experts.

These and other common exercises that bend the spine are not for everyone: They could cause serious back pain and even spinal fractures for people with low bone density or osteoporosis.

Sara Meeks, a physical therapist and osteoporosis expert, told the American Physical Therapy Association recently that she considers everyone at risk from spine-bending exercises until a test shows they have normal bone density.

Spinal vertebrae, Meeks explains, can crush or break easily if they have been weakened from bone loss or osteoporosis. And that afflicts more than just older women.

"We think of osteoporosis as an old person's disease, but the fact is this is a condition that's occurring in children, even young children," says Meeks, author of Walk Tall! An Exercise Program for the Prevention & Treatment of Osteoporosis.

Some 10 million Americans have osteoporosis, and another 18 million suffer from low bone mass, the National Osteoporosis Foundation reports. It blames osteoporosis for more than 1.5 million fractures annually, including some 700,000 vertebral fractures and 300,000 hip fractures.

Meeks, who is also chairwoman of the American Physical Therapy Association's osteoporosis group, says there's a "vast void of information," even among fitness instructors and trainers, about the inherent dangers of sit-ups and crunches -- as well as toe touches -- for those with low bone density.

And most of those with low bone density are unaware of it, she says. Osteoporosis is often called the "silent disease" because bone loss occurs without symptoms. Victims may not realize they have it until their bones become so weak that a strain, bump or fall causes a fracture or a vertebra to collapse.

In women, osteoporosis is linked primarily to a sharp drop in estrogen after menopause because estrogen slows the natural loss of bone that begins around 30. In men, low levels of testosterone from impaired hormone production contribute to osteoporosis.

But Meeks said many other factors increase the risk of low bone density. Among them: a sedentary lifestyle, poor posture, smoking, excessive drinking, calcium or vitamin D deficiencies and eating disorders.

Lucy Buckley, a physical therapist and liaison between the American Physical Therapy Association and the National Osteoporosis Foundation, also stresses the importance of choosing exercises carefully to avoid injury.

"All exercise is not the same by any means, and people need to make the distinctions," says Buckley. "Older people or people at risk [of low bone density] had better be advised of this because they could be doing bad things to themselves."

Abdominal crunches, for example, are often seen as a "holy grail," Buckley says. But those at risk should choose alternatives that cause less spinal pressure.

"We physical therapists," she says, "have to preach our message louder that all exercise isn't the same."

(From Healthscout)