Making a game character run like an actual person using AS3

Hi,

just wondering if anyone can help me with this
I’m making a platform game and wanted to make my game character run when user press the keyboard left or right. But I want my character to run like an actual person instead of just sliding across the screen. I have no idea where to start and I can only find tutorial that teach how to make a character move by just using - or + number of pixels but that’s not what I’m actually looking for. I prefer that my game character to be more lively. Does anyone know how??

Thanks