[Barbell Squat] mainly trains the thighs.
Place the center of the barbell at the trapezius muscles of your shoulders, hold the barbell forward with both palms, place the soles of your feet shoulder-width apart, and slightly abduct your toes.
Using the tension of the quadriceps, slowly bend your knees and squat until your thighs are parallel to the ground. Be careful not to lift your heels off the ground.
Use the contraction force of the quadriceps to stretch your legs and stand up until your legs are straight, so that the thigh muscles are in the "peak contraction" position. Do 3 sets of 6 to 12 reps every other day.
