A speedster is a character whose powers primarily relate to superhuman speed. Primary abilities shared by all speedsters include running at speeds far in excess of human capability and resistance to the side effects that result from such velocity. In almost all cases, speedsters are able to physically attack opponents by striking them while at high speed to impart huge amounts of kinetic energy without suffering harm. A variety of other powers have been attributed to speedsters depending on the story, the origin of the power, and the established continuity and rules of a given universe.
The use of speedsters in fiction requires artistic license due to the laws of physics that would prohibit such abilities. Moving at the speed of sound, for example, would create sonic booms that are usually not heard in such stories and generate substantial heat. An enormous amount of energy would be required to achieve such speeds, and as some speedsters can actually move close to or at the speed of light, this would cause them to gain near-infinite mass, according to the laws of relativity. The Official Handbook of the Marvel Universe states that the character Nova maintains speeds which can be considered "modest", especially when carrying a passenger. The Handbook also concedes that a solid object moving in the Earth’s atmosphere at several times the speed of sound or faster would wreak havoc on the planet and that moving at such speeds would prohibit Northstar from breathing, while the generated wind/friction would ravage his body. On the other hand, the Handbook states that the character Quicksilver was born with adaptations that make higher speeds possible, such as enhanced cardiovascular, respiratory, musculature, and digestive systems, a more efficient metabolism, better lubricated joints, tendons with the tensile strength of spring steel, unidentified bone composition that can withstand the dynamic shock of his touching the ground at speeds over 100 miles an hour, and a brain that can process information fast enough for him to react to his surroundings at high speed. In DC Comics, the Flash family of speedsters derive their abilities from an extradimensionalenergy source known as the Speed Force, which grants them superspeed and various other abilities required to use it, such as durability. However, the Speed Force is not the source from which other DC characters with superspeed such as Superman or Captain Marvel/Shazam derive their powers. Writer John Byrne maintained modest abilities for the speedster character Danny Hilltop in his series John Byrne’s Next Men. Although Danny can keep pace with a race car, the friction generated by his speed melts any footwear he wears, burning his feet. Thus he runs barefoot, having toughened the soles of his feet through a regimen of pounding increasingly harder materials. Other writers choose not to offer any scientific explanations for the questions raised by the actual use of such abilities. Peter David, whose run on the series Young Justice included the junior speedster Impulse, has opined that speedsters are inherently difficult to write: "Speedsters make me nervous, because if you play them accurately, they're impossible to beat... I could deal with Impulse because he was easily distracted." Some speedsters may also end up destroying their surroundings or entire astronomical structures around them by their sheer speed alone if they are not careful enough.
Characters in the Dragon Ball franchise like Goku, Vegeta, and Frieza, who are able to react and keep up insane speeds. During the Universal Survival saga, Dsypo is said to have surpassed the speed of sound and light in his past battles and currently is faster and able to increase his speed several thousands of times. Other characters are as fast if not even faster than Dsypo.
Dash Parr of the Pixar motion picture The Incredibles
Bree Davenport, the superhero from Lab Rats
All Kamen Riders from Kamen Rider Kabuto, who have the ability to "clock up" and move at supersonic speeds. While Kabuto himself is most well known for being the fastest Kamen Rider, there have been other Riders before and after him with similar abilities as well.