Vastus Lateralis of the Quadriceps

The vastus lateralis is located at the anterior outer region of the upper leg, and is a muscle that is part of the collective group of muscles commonly known as the quadriceps (which are located at the front of the upper leg).

The vastus lateralis is responsible for the ‘sweeping’ appearance of the quadriceps.

The vastus lateralis is responsible for the extension of the knee, and exercises that require this action will recruit the vastus lateralis effectively.

The squat requires many muscles to stabilise and act as synergists to the lift, and is seen as the champion for lower body devolvement. The vastus lateralis, along with the other quadriceps muscles will be recruited strongly during the squat. The squat can be viewed in the exercise section to the right.

If direct stimulation is needful then isolation of the extension of the knee will provide advantageous, such as leg extensions. This may be the case for people who want to place stress directly on the quadriceps muscles, and not a lot of secondary muscles. It should also provide beneficial for those who may have injuries and find the squat an inferior choice as it places too much stress on the injury, or feels uncomfortable.
Isolateral training is also possible with the likes of leg extensions. Exercises can be viewed in the exercise section to the right.

6-12 reps will likely provide optimal time under tension for most the quadriceps muscles, providing adequate stimulation for sarcoplasmic hypertrophy, and acute response to anabolic hormone concentrations, compared to that of lower rep ranges.
If however strength is your primary goal then 1-5 reps with an exercise such as squats will likely lead to the best recruitment of the large motor units and type iiB fibres, and neural adaptations of the nervous system. One can also master the technique of the squat, which should in time lead to better execution of the lift, and therefore better poundages being shifted.