Sit down in the leg press machine and place your feet on the upper half of the platform spaced slightly wider than shoulder-width apart. With your toes pointing slightly outward, press the weight up, remove the stoppers and grip the handles firmly. Lower the weight down as far as you can without putting any stress on your lower back. Drive the weight back up to the starting position but don't lock your knees out at the top. When you have completed your set, put the stoppers back in place and set the weight down.
Tips: It is important to use a full range of motion on this exercise instead of piling on the weight and only performing half reps. Lower the weight down as far as you comfortably can to maximize muscle stimulation. Also remember not to lock your knees out at the top of the movement as this will keep the stress on your thigh muscles at all times and will prevent injuries to the knee joints.