"Dumbbell-loaded side bends are worthless. People think you can spot reduce fat, but it doesn't really work that way," says Gahan. Here's why: "You are breaking down muscle, then building up later by ingesting protein, but there isn't enough resistance in this exercise to effectively challenge the muscle, so the net effect is zero," she says. "If you want to impact your side torso, obliques, and lower-back region, try oblique push-ups, instead," she says. Here, you rotate your leg underneath you as you push down toward the floor.