Dumbbell Step-Ups Find a step, kids' chair, or bench that, when you place your foot squarely on it, your knee is at a 90-degree angle or larger. Hold a dumbbell in each hand by your side. Step up onto the chair and lift your right knee forward and up. Lower the right foot back to the ground, landing softly. This counts as one rep. Do as many reps as you can for 30 seconds, alternating which leg you step up with each time. Image Source: POPSUGAR Photography