If you are worried about your shutter speed dropping below the value needed, try using your camera’s Auto ISO feature. Some DSLRs enable you to set a minimum shutter speed, which the camera maintains by altering ISO sensitivity.
IntentIonAL BLur Any lack of sharpness should be clearly intended
Not fast enough
Although the stadium lights at this dog track looked bright, the shutter speed was still surprisingly low at ISO 1600
Freeze the action
Aim to keep your exposure above 1/1,000sec. An increase in sensitivity to ISO 6400 was needed here