Speed is determined to a great extent by the genetic factors. The study of physiological Factors help to select the activity for an individual.
1. Mobility of the nervous System :- The rapid contraction and relaxation of muscles is made possible by the rapid excitation and inhibition of the concerned motor centres. Nervous system can maintian this rapid excitation and inhibition for only for a few seconds. After which the excitation and inhibition for only for a few seconds. After which the excitation spread to the neighbourning centres causing tension in the entire body. This results in decrease in speed. The mobility of the nervous can be trained only to a very limited extent.
2. Muscle composition :- The muscle, which has more percentage of fast twitch fibre, contract with more speed in comparison to the muscle which have lower percentage be slow twitch fibre. The muscle position is genetical and can not be changed by training.
3. Explosive strength :- For very quick and explosive movements, explosive strength is indispensible. It depends upon metabolic composition, muscle size & muscle coordination. The explosive strength of the muscles can be improved through training.
