Super speed can be described as the ability to physically move and execute various actions far more quickly than the average person.
Various theories are tied to the effects of super speed. In one school of thought, those individuals physiologically unequipped to deal with the rigors and forces inflicted upon their body while utilizing super speed will incur ligament and/or tendon micro tears and similar injuries that also appear in the bodies of veteran professional athletes, especially football players.
Another theory posits that when an ordinary human gains super speed, his or her mind is unequipped to process sensory input at an effective rate when moving at or beyond a certain speed. Inevitably, mistakes are made, including but not limited to tripping and running into things at a dangerous and potentially fatal rate.
A third possibility in the world of super speed, and the most "positive" of those presented thus far, explains super speed relative to time distortion. Instead of the individual moving faster but thinking and reacting at a usual rate, the individual senses the ambient world moving more slowly. Thus, there is no risk of encountering a situation and not being mentally capable to handle it when experiencing this type of super speed. Such moments of mental time distortion have been reported by various normal humans in exceptional and often emergency circumstances, especially when machines have been involved. Certain drivers have reported that just before a crash, time seemed to slow down for them, although they could not move quickly enough to alter their course sufficiently. An individual possessing this level of super speed would be able to both mentally slow time down and physically adapt so as to "catch up" to the newly heightened temporal perception.
Another version of the time distortion school of thought entails the individual not slowing time down in his or her mind, but actually bending time around him or herself, effectively slowing time down in reality, while maintaining his or her current rate. In an extreme version of this, the individual actually stops time, and therefore begins moving at an infinite rate, although to him or her, it doesn't seem that fast at all. As in the previous example, there is usually no risk of movement overtaking mind, and an added benefit provided by the "actual" time distortion is the absence of the accumulation of micro tears along tendons and ligaments, as well as similar injuries.
An individual already possessing extraordinary physical resilience or regeneration, or mental acuity and speed far sharper than usual would likely not encounter the full range of low-level super speed issues. An individual operating on a higher time distortion level would also have less of this to worry about.
The fastest reported ground speed by a human being on foot, allegedly without the aid of performance-enhancing drugs or technology, is upwards of 37 kilometers per hour.
While the use of drugs has been a topic of great intensity, substances such as steroids would be a highly ineffective means at attaining super speed. This is mainly because the gains they offer in performance can be considered to be by a certain standard small. They may produce results on the "regular" level, because in the world of competitive sports, every little bit helps. Shaving a few fractions of a second off your time in an event by using steroids can mean earning the gold instead of the silver (illegally), but such an increase in speed is of little importance when confronted with super speed. In the world of superpowers, steroids essentially offer an advantage of zero.
One possible way to legitimately achieve super speed would be to use technology integrated with human physiology to consistently and powerfully stimulate the adrenal glands. Additionally, muscular efficiency could be improved with technology capable of making modifications at a molecular level. However, there would likely be upper limitations connected with the way in which the human body is engineered. Granted, the gains in speed theoretically could be immense, but it is unlikely that this kind of improvement could approach the greater limits of fictional super speed, which occur at and beyond the speed of light.
The healthier you are, the faster you can move without hurting yourself. Get adequate rest, stay hydrated, eat a majority of wholesome foods, and exercise regularly. If your goal is to run faster, run more. Be careful not to overstress yourself. Start slowly and work your way up. If something doesn't feel right, don't force it. Exercise on a bike, even a stationary one, can help with sprinting, and using an elliptical rather than pounding the pavement will reduce the strain on your joints. Remember to stretch, and keep in mind that muscles grow when you rest, not when you exercise.
If you want to be faster at something in particular, you might want to try overlearning. This is a concept under which one continues to reinforce material even after it is learned well, so as to ultimately reach a point where he or she can recall it or put it to use with a minimum of focus. Essentially, it all comes down to the old saying, "Practice makes perfect."