When trying to capture an action shot, such as a person cycling, or anything athletic and high speed, your camera's shutter needs to also be fast. Especially if you want your subject in motion to be crisp and in focus. If you're trying to show a sense of speed by having your subject be blurry, such as a car racing by, then use a slower shutter speed. Of course, how long your shutter is open will affect how much light gets to the sensor, so make sure you understand how the other settings on the camera work to get a properly exposed, properly focused shot. You can browse our other blog posts for information on that.