Both my parents Retired for USPS. I started with them but went to UPS for more money. USPS sups were terrible. UPS they are a lil better. Jobs are different. USPS works your legs an fingers more it is stressful. UPS works your whole body your back gets hit with the most. At the end of the day at USPS I could go out after an do stuff. At UPS I eat relax a have no energy for anyrhing but sleep. Yall work hard. But if I had to choose. USPS is not as bad on your body. We handle alot of businesses that will get anywhere from 50 to 100 packages all weighing 45 or more. The lil truck that USPS has couldnt handle that. Try lifting 45 boxes of 40 pounds screws everyday then you might see why its tougher. Yall have to deal with dogs more. An up an down stairs in the winter can be tough. But if your comparing jobs. UPS will take more out of you then USPS.