Learn to relax. This is the key to discipline. Tension and stiffness of your muscles will always impede movement.
Use of various equipment gymnastics to improve the response. You will train muscles and learn how to better control them. For example, one of the exercises involves re-training method. Need as quickly as possible and to repeat several times train movements to signal, such as running from the start or squats. The body will remember, and the response will improve.
Play computer games. Quest or game-a"Walker" allows your character (and therefore you) to pass certain stages, to overcome difficulties, to be attentive and solve a variety of tasks. These games can improve coordination hand-eye and develop good reflexes.
Try to learn to knit, embroider, weave, or just take a course of restropective using all the fingers. This activates your nervous system, will help to improve the overall health of nerves and definitely will improve reaction!
Always be in good shape to keep your skills up to a ripe old age. Avoid food fast food and foods, eat enough fruits and vegetables. Exercise, proper sleep and proper nutrition are the key to quick reaction.
Training responsiveness will take some time, but soon you will notice an improvement. And even be able to sports and other victories.