Running 25 to 30 miles a week might keep the fat off, but it isn't going to add much muscle to your butt. If you want a strong, hard ass, squat with weights, do wide split deadlifts, hip thrusts, and sprint.

hip thrusts -- do them first with bodyweight and then progress with barbell weight
check out the "glute guy," fitness guru bret contreras at bretcontreras.com

Running 25 to 30 miles per week does it for me. It sounds like this is just your anatomy.

I think a lot is genetics

Running up steps

Lunges and squats. But if you're genetically flat-assed, not much you can do about it other than plastic surgery.

Full squats with heavy weights, deadlifts

Cycling

Lunges

Spinning.

Core not cite

OP here. I do a set of cite exercises from a Runner's World magazine but they seem to mostly target abs.

Walking lunges with weights, squats, plies ( not sure that's spelled right--- suppose to read 'plee ays') should do the trick

What core work do you do?

Please tell me what to do.....
I run 25-30 miles per week. Have a flat butt! Yuck. What are the best exercises?