The more skilled you become at shooting action shots, the more you learn to use slow shutter-speeds and use the subjects' motion to highlight the important activity and give the image impact. At a slow shutter-speed, you should, with practice, be able to completely blur the boxers' arms, legs, boxing-ring, and audience, but capture that moment when glove makes contact, making it the most sharp and abrupt part of the image. In this case, pun intended, a real moment of impact. Using the motion blur to frame and focus the most important part of the image, leading the viewer's eye there. Not unlike the same way that shallow DOF is used to isolate a part of the subject from foreground and background, but in this case it is accomplished with motion-blur.

This takes practice with both knowing how to quickly pan and follow a subject as well as knowing your subject to know how it will move, and the limits of how each movement might stop abruptly or halt motion during a sudden change of direction. Examples: snapping off a shot at the peak of a jump, or when a football player makes a 180-degree turn on the field, when a baseball hits the bat. (These skills are also invaluable in wildlife and birding photography, but then you must also know animal behavior as well as you might know human behavior.)

Too often people assume they need the highest shutter-speeds for action photography, when actually some of the best shots ever taken of these kinds of subjects were with slow shutter-speeds and low ISOs.