A lot of people seem to think that doing squats and/or deadlifts is going to give them a sore back... wrong. Doing squats and deadlifts will actually strengthen your back, IF you do them with the correct technique.
There are a variety of ways to do squats and deadlifts, depending on what you want to get out of your training. For example, a powerlifter isn't going to squat the way that I squat, because I simply want to build strength, not squat until my knees snap (horrible flashbacks to that video that's going around Facebook at the moment).
These exercises predominantly use your leg muscles, but actually help strengthen all over (core, back etc). And I think it's important to remember that if you want to burn fat more effectively, you need to get yourself some more muscle, so head down to the gym and use these techniques to improve your technique, lift heavier and get more results: