What does speed do?

Answer 1

Drug : Speed enhances your stamina, delays physical fatigue and increases heart rate. It also intensifies your senses, you can hear, feel, smell better than before. In sports, this can be used as a performance enhancer, even though there are much better products on the market.

It has a huge downside, besides being illegal, it takes all of the energy you 'recieve' out of your body's natural reserves. And thus, you need time to recover. If you do not take the time to recover, your body starts decomposing its muscle tissue in order to feed itself. So in the long run, you're actually getting weaker.

Your kidneys and liver also take a lot of damage from speed (ab)use.

It can be found in various prescription drugs of the kind given to people with sleep disorders in order to keep them awake.

Answer 2

In boxing speed is needed in both your feet and legs as well. Then you can hit the other boxer more blows, and you can also Dodge him if you have fast dancing feet.

Answer 3

speed is important because if you have speed then you can move quicker therefore making you more of a challenge for your opponent.