Working at United Parcel Service (UPS) is a backbreaking, grueling job. Few people last even one year. Most who work there for a long period of time have back and/or joint pain. The main jobs, loading the trucks or delivering packages in the boxy brown trucks, are especially taxing. The loading jobs are so rough that UPS only wants part-timers to do them, figuring no one can handle the job for a full eight hours.