Mary Ann Wilson is the creator and host of the "Sit and Be Fit," a senior fitness program that has aired on US public television since 1987.

The majority of her viewers are women over 65.  For that population, she said, the goal of exercise is health and well-being, not physical prowess.

"Gravity has been working on them for 70 years," said Wilson, a registered nurse who specialized in geriatrics. "Gravity is not our friend after many years of pulling our heads, shoulders and upper torsos forward and down."

The 30-minute class includes warm-up, circulation and strength segments, a finger segment (for stiffness), standing for balance, and final relaxation.

Posture, breathing, balance, cognitive functioning and reaction time are among the most important-and neglected-components of elder fitness, she said.

"Focusing on gait is really important because as we age our gait changes," said Wilson.

Karen Peterson, author of "Move with Balance: Healthy Aging Activities for Brain and Body," stresses a mind-body approach in workouts with seniors.

"In our society it seems people don't really like to do things unless they're good at it already," said Peterson, a kinesiologist based in Maui. "But what the brain likes is to be challenged."

Her exercises include tossing a bean bag to improve reaction time, walking a figure-eight pattern for balance, as well as eye stretches, jaw relaxers, childhood games and cognitive challenges to keep body and mind alert.

"We take balance exercises and add conversation or math problems," she said. "The concept is to always progress, always get more challenging."

To tackle the isolation and diversity of the older population, Peterson initiated a mentoring program in which the fitter seniors work with the frailer.

"Some partners will become friends," she said. "They'll get really turned on."

Experts agree that it's never too late to do something. "Exercise is effective even in the most frail individual," Wilson said. "If they can wiggle their toes, they can exercise."