A lunge can refer to any position of the human body where one leg is positioned forward with knee bent and foot flat on the ground while the other leg is positioned behind. It is used by athletes in cross-training for sports, by weight-trainers as a fitness exercise, and by yogis as part of an asana regimen. Lunges are a good exercise for strengthening, sculpting and building several muscles/muscle groups, including the quadriceps (or thighs), the gluteus maximus (or buttocks) as well as the hamstrings.
A long lunge emphasizes the use of the gluteals whereas a short lunge emphasizes the quadriceps. The lunge is a basic movement that is fairly simple to do for beginner athletes. A lunge can be performed using bodyweight alone. However, weight trainers may seek to increase the difficulty using either dumbbells or kettle bells held in each hand, or a barbell held atop the neck and shoulders. Grip strength may be an issue with the dumbbell lunge so practitioners may prefer the barbell lunge. As a variation, plyometric lunges (also known as split squat jumps) can be performed by jumping explosively between lunge positions.