If your subject is moving across your frame, leave more space in front of the subject, so that he/she/they appear to be moving into the picture, and not out. Think of it like this: the guy needs space to move into. Or imagine you’re the one who’s running. Would you like to have a stone wall a few inches in front of you?
If you just don’t get it, have a look at this version of the same picture.
See what I mean? All wrong, isn’t it.