A cinema camera has had 24 fps since around the 60's, bruce's fighting was really shotty on camera, it looked fake with him at full speed, so in order for it to look fake his speed had to be around .03 seconds a punch. That would add up to 8 in 1 second. 8 pictures in 1 second would look hell of crappy. In fact he was probably a bit faster but hey who really knows? This is an estimation. If the fighting looked fake his speed would of had to be somewhere around there.