Jane Fonda on Valium--that's what Leslie Sansone seems like in Walk & Firm for Older Adults. But that's a good thing, especially if you're the "older" person this half-hour is aimed at. Sansone takes you through her gentle in-home walking program with a peppy (but not too chipper) spirit on a set that looks like a barely furnished living room. She doesn't bother with a cast of dozens--it's just you and your private exercise guru. After a low-key warm-up that includes walking, mild kicks, and mini-squats, the pace picks up. Mild aerobic exercise is interspersed with firming and strengthening, using weights of 2 pounds or less. Throughout, she cautions against doing a move that seems too difficult or using a weight that feels too heavy. This is aerobics for the reluctant exerciser: The only thing that really matters is that you keep moving. --Valerie J. Nelson