Superhuman Speed (or Superspeed) is the biological ability of a DNA Alternate to enlarge their suprachiasmatic nuclei, increasing their circadian rhythm exponentially, and allowing them to operate at a higher speed. The Alternate with this ability can often move faster than the speed of sound and may be nearly impossible to catch on video cameras, even completely slowed down. If the Alternate does not wish to be caught, in general, they won't be.
The increased circadian rhythm has a number of side effects, not the least of which is a vastly heightened metabolism. The Alternate will consume exponentially more calories to fuel their enhanced speed, and their body will respond by healing injuries more quickly. The Alternate will think fast, talk fast, and age fast. Most Alternates with superhuman speed do not live past seventy.