The dumbbell step-up is a multi-joint, single-sided strength movement for the lower body, emphasizing the quads, hamstrings, and glutes. The exercise also improves core strength and stability.
Hold a pair of dumbbells at your sides and place one foot on a bench or box, your knee bent to 90°. Keeping the other leg straight and firmly planted on the ground, push your shoulders back and chest out.
Push through your top foot to raise your body over the platform, your back leg suspended in the air. Push your hip back to lower your support leg back to the floor.
Do not use the leg on the ground to help lift yourself onto the box.
Keep the working leg planted firmly on the bench. Don't rise onto your toes.
Do not let the knee of the working leg cave inward.