Just like every animate object, every superhuman with enhanced speed can move at varying degrees of speed. Some speedsters can move at the speed of sound, others can move 500 times the speed of sound, and more extreme examples can outrun time itself. Whether if it is the user’s running speed, reflexes, maneuverability, or jumping capability all of these have varying degrees of speed. Also, just like exercising any muscle the user’s speed will gradually increase the more they use it. I am thinking of having one of my characters in my sequel spin-off a speedster who starts off slow before gradually increasing their speed throughout the story.