Mention the word "exercise," and you're likely to hear groans. It's one of those "shoulds" people know is important to health, yet just one in three American adults exercises regularly.

Aversion to the "e" word is so strong that many health professionals now substitute more acceptable terminology such as "physical activity" or "movement."

Yet beyond the semantics and the easy excuses ("no time," "too tired") are often some deep psychological issues, says registered dietitian Francie White, a Santa Ynez, Calif., expert on eating and body image problems.

"Eating behaviors often have an emotional component, and exercise patterns can, too," White says. "In counseling women with overeating disorders I've found that many do not simply neglect to exercise, they actively resist it."

Blocking It Out
White has coined the term "exercise resistance" to identify what she calls "a conscious or unconscious block against becoming regularly physically active." In an article for the journal Women's Health Issues, she describes two general patterns:

• Unconscious resistance -- where someone sets exercise goals, starts a program, then sabotages it and quits.
• Active refusal -- where someone experiences anger, despair or feelings of futility when exercise is recommended.

"Just as eating disorders vary from starvation on one end of the spectrum to compulsive overeating on the other," she writes, "so, too, do exercise patterns range from exercise dependence to exercise resistance."