Photo SpecialLook Who's Fiftysomething!

BACK TOGETHER

It's been 20 years since the 1987 debut of thirtysomething, but the ABC hit's four female stars – Polly Draper, 51, Mel Harris, 50, Melanie Mayron, 54, and Patricia Wettig, 55 – are as close as ever. Reunited as ambassadors for Tylenol's Keep Moving arthritis-prevention campaign, the women sat down with PEOPLE's Pamela Warrick to talk about how they're looking great as fiftysomethings.

(More information on the Keep Moving program, a joint venture launched by Tylenol and the Arthritis Foundation to educate Baby Boomers about ways to ease the aches and pains of aging, is available at justkeepmoving.com.)