Standing with a much narrower stance while you squat targets the inner thigh, inner quad, and inner hamstring. There is no reason not to multitask on this move — so work your arms too. Here's how.
Stand with your feet touching. Hold your hands comfortably in front of your chest to help you stay balanced and bend your knees, lowering your hips deeply, bringing your thighs parallel with the floor if you can. Be sure to keep weight back in your heels.
Then rise back up, straightening the legs completely, squeezing the glutes at the top of the movement to get the most out of the exercise.