Physical training is a must to be a good competitor and have success on the field. A high player (or a player that aspires to play at a high level) must have stamina to stay sharp, make good decisions quickly, and maintain an overall high level of play for the entirety of the match. One of the first areas that suffer is the players ability to process information and make good decisions when he or she is tired. The second area that suffers their motor control, the players ability to quickly and precisely control your muscles, in result your technical also suffers.

Players with superior speed and strength usually have more impact due to the fact they can: 

1. close down space faster,
2. withstand and play through physical contact with balance
3. win more 50/50 challenges
4. be an overall better competitor

1. ball control
2. foot speed
3. reaction speed
4. and agility

Again if you can control your body well it well reflect in your control of the ball. However there is a lot more to being physically fit in addition to physical training, like a players nutrition, sleep pattern, and stress management.