Ready to lose the baby weight? Find the nearest staircase, park that stroller nearby, and follow this plan designed by Erica Ziel, a trainer in Newport Beach, Calif. and creator of Knocked-Up Fitness. You may have used stairs for cardio, but it turns out they’re great for toning, too. “Doing an exercise on an incline like a staircase intensifies it, making it even more effective,” Ziel says. This sequence burns up to 300 calories in one 30-minute sesh. That’s next-level awesome!