To perform the BarBell Side Lunge, begin with the rack set for chest height. Position the bar on the back of your shoulders, gripping the barbell to the sides. Next, lunge to one side with your first leg. Land on your heel before your forefoot. Lower your body by flexing your knee and hip of your leading leg. Be sure to keep that knee pointed in the same direction as your foot. Return to standing position by forcibly extending hip and knee of lead leg. Alternate with your other leg.