Want to work those quads? Try dumbbell wall sits! Get into the position by leaning your back on a wall and then lowering down. When you get to a point where your thighs are parallel to the floor, that's a good place to stop. Make sure your feet are about hip-width apart. Try to make the knees square so they don't go beyond your toes. Now, place the dumbbells on your groin area to add in even more resistance. Extend your arms in front of you, hold this position for about 30 seconds and repeat 3 times.