By working one muscle or muscle group or even one area of the body per workout, you focus on building or training that area. But this comes at the expense of working other areas. If you do it correctly, a full body workout can help you meet your fitness goals more efficiently.
More Muscle Building
The efficient way to build muscle is by using higher loads and fewer reps. Repeating the same heavy lifts many times may not provide any extra benefit to justify not working other parts of the body. For example, unless you are a professional bodybuilder, two sets of an exercise, rather than three or more, are sufficient for muscle building, allowing you to do more exercises during your workout. Full body workouts work all of your muscles, which is better for you if your goal is not spot-building muscles.
Burn More Calories
Some workouts focus on your lower body, upper body or core. The focus on one area may burn fewer calories, because you're working fewer muscles and may need longer rest periods. If you are working your legs only, it may be difficult to move from squats to dead lifts to lunges to leg presses without more and longer breaks between each. If you are circuit training your entire body, your legs can rest while you do biceps curls, triceps kickbacks or chest presses. After the lower and upper body workouts, you can move to core exercises.
Many people stop exercising out of boredom. Full body workouts let you pick and choose any exercise or type of exercise you wish. You can use free weights or weight machines, cardio machines, calisthenics or aerobic dance routines. The more fun you have doing exercise, the more likely you are to exercise longer each session. Variety and enjoyment will encourage you to continue your fitness program.
If you can only exercise two or three times per week, you can work each muscle more often if you do full body workouts. If you work one area per workout, you might only be able to work your legs, hips and glutes once each week, and your upper body once and your core once. Full body workouts let you repeat bodybuilding reps or work on muscular endurance training three times a week, using the same muscles.
You will not have time to do as many sets and reps of an exercise during a full body workout as you do during a dedicated, one-area workout, so you are less likely to over-train muscles. This also prevents repetitive stress injuries that can occur when you only work one area of the body over and over.