When i bend over i have a hump in my back i do a lot of gym work and general exercise, when i stand up right my back looks fine?

Scoliosis: A possible reason for a hump that is visible when bending over is scoliosis. A full spine x-ray would better identify this condition.

See below: When we bend over the natural curves in our spine reverse and we all have a "hump" in the middle of our back. If your back looks normal when you are standing up i doubt there is anything wrong. If you are worried, see your doctor to get checked out.