Snatch-grip deadlifts are similar to standard deadlifts except that the grip is much wider. In most cases, lifters will need to use straps to maintain grip in the snatch-grip deadlift. The wider grip forces you into a lower position, almost into a full squat. This lower position also changes the position of your torso, thus requiring more of the emphasis on the entire back, hamstrings, and glutes.
Because of the lower position of the deadlift, there is more muscle recruitment from the upper portion of the back, as opposed to the regular deadlift, in which, more muscle recruitment is in the lower back more stimulated. The wider grip makes your upper back and rear deltoids work extra hard to keep the bar close to the body, especially during the lowering portion of the exercise. This not only shapes and defines your back, but can also improve your posture.
The lower position, in which the hips are lower to the ground, forces your hamstrings to work hard to pull up from the low position. This is important not only for bodybuilding and powerlifting, but also improving overall leg strength. Runners need strong hamstrings to aid the hip extension. Whenever you can involve the hamstrings more, the better off you are for building leg strength and speed.
Much of the emphasis in the snatch-grip deadlift is also placed in the glutes. This exercise is just as effective at targeting the glutes and building up the quadriceps as performing full barbell squats, with the added benefit of less lower back involvement. Exercises such as the deadlift are more effective at strengthening, building and shaping the glutes then exercises that are performed on a machine. The snatch-grip deadlift offers a greater range-of-motion, thus allowing for greater muscle recruitment in the glutes and quadriceps.
Powerlifting exercises such as deadlifts can severely tax the cardiorespiratory system if done with enough intensity. The high-intensity of the deadlift challenges the body both aerobically and anaerobically. This forces the body to burn more calories not only during your workouts, but long after your workouts are over. Additionally, new muscle gained from regularly performing the deadlift will increase your resting metabolism, thus helping you lose extra fat weight.