"Put it in your calendar," says trainer Danny Musico, who gets the cast of Entourage buff. Hire a trainer so you can't back out, or set a date with your husband and friend. Travel too much? Pack an exercise DVD or resistance brands, which take up zero space, or hit the streets with your sneakers on. A brisk walk after a long flight can get your blood pumping and endorphins flowing.
SPRI Xertude resistance band, $14; at amazon.com.Read MoreLess