The Power of a Gentle Nudge [news]

Phone calls, even voice recordings, can get people to go to the Gym. Unable to push herself to exercise, Ruthanne Lowe joined a research study aimed at motivating the sedentary with a surprisingly simple technique—an occasional telephone reminder.

"It really did work," says Ms. Lowe, a 66-year-old housewife in San Jose, Calif. Three years after the study ended, she says, "I'm doing more exercise than I ever did in my life."

The study, conducted by Stanford University, belongs to a growing body of research showing that small amounts of social support, ranging from friends who encourage each other by email to occasional meetings with a fitness counselor, can produce large and lasting gains against one of America's biggest health problems—physical inactivity.