While different exercises focus on different muscles, all the parts of the body are still required to work together, making upper body exercises essential for the successful athlete. Additional upper body exercise is naturally beneficial for swimmers, who depend on their shoulders and arms to propel them, but strong arms are also important in running, biking and aerobics. Strengthening your upper body, especially the shoulders and back, will give you the posture to fight unnecessary injuries and maintain form in lengthy, grueling workouts. Toned and strong arms will also help propel you in other exercises that rely heavily on your legs. Working the upper body also has its benefits in strengthening abs and core muscles, and helping you burn calories at a faster rate.

Solid posture is important for aesthetic appeal and to prevent back pain even when you're not working out, but it holds an entire other layer of benefits for athletes. The best way to achieve proper posture is to tone back and shoulder muscles, strengthening them to hold the top half of your body up. Distance runners especially benefit from a strong upper body, as shoulders tend to slump and hunch as runners get fatigued. The drooped posture will ultimately slow runners down and could result in injury for them once they're done running. Strong shoulders are also important for those who bicycle for exercise. Those riding for speed bend the top half of their body toward their handlebars, with arms and shoulders taking a good chunk of the impact and force of the ride.

A strong upper body will help you maximize the benefits of even the most leg-heavy types of exercise. Many elliptical machines have spots for you to pump your arms, so solid shoulders and biceps will help you move at a faster pace and consequently burn calories at a higher rate. Strong arms and shoulders can also give runners an essential boost of speed and a solid upper body can help them maintain balance. Exercise your upper half to get that agility and final burst of swiftness as your approach the finish line.

Even if you take little time out of your schedule to exercise, chances are the lower half of your body is getting a workout, as you walk from place to place. The upper body doesn't have the luxury of this built-in workout, though, and will remain flabby and un-toned unless you take the time to exercise it. While you may not care if you have the appearance of strong biceps or pectorals, it's beneficial to have muscle wherever you can. At rest, muscle tissue burns the body's calories faster than fat does, so toning your entire body will create a more efficient way to burn calories and ultimately lose weight. Additionally, most upper body exercises require a tightened core to keep balance and form, so pumping iron for your uppermost muscles will also enhance your abs. The upper body isn't a single entity, though, so be sure to work the different muscle groups to get the biggest benefit.