During a soccer match, the number of offensive and defensive players on the field varies depending on the age of the players. While adults play with the standard number per team, the US Youth Soccer recommends that children younger than age 12 play "small-sided games"

The position at which a soccer player becomes a specialist can often be determined by his physical height and stature. However, this is not always the case. A player who is strong and powerful will have different strengths and weaknesses compared to a player shorter in stature but also fast and nimble on his feet.

The game of soccer is governed primarily by rules from the Federacion Internationale de Football Association, or FIFA. One of those areas governed by FIFA is the quality of the ball used in competition. Air pressure of the soccer ball is one of those topics covered in the laws of the game.

The position of soccer goalie necessitates playing the last line of defense for your team. Playing goalie, or goalkeeper, requires leadership skills, confidence, perseverance and the ability to stay calm and cool-headed, even immediately after a mistake.

Manchester United star Wayne Rooney lifts weights according to a custom plan developed by his team trainer. The players for DC United perform a combination of lifting in the weight room and resistance exercises out on the practice field.

Want your child to be king or queen of the playground during recess kickball? There's no better way for them to succeed than to know how to blast a kickball great distances.

Soccer goalkeepers spend most of the game far from the action, yet they often stand out from other players due to their bright, distinctive uniforms. Some goalkeepers wear different uniforms for practical reasons, while others do it to enhance their personal style and perhaps intimidate their competitors.

The National Federation of State High School Associations, based in Indianapolis, Indiana, sets high school soccer rules in the United States as well as rules for 15 other sports. Founded in 1920, the NFHS largely borrows from the Laws of the Game set by FIFA, the international governing body of soccer.

The goal box, also called the penalty box, in soccer is an area 18 yards square. It is the area in which the goalkeeper, but no field player, can handle the ball. Its primary purpose, therefore, is to mark out the goalkeeper's area of influence on the pitch.

Although soccer requires running, it is not considered an aerobic sport. The American Council on Exercise says that because soccer requires many starts and stops, your body functions at an anaerobic level, meaning without oxygen.

Soccer fields feature two distinct boxes in front of the net. The large box is the penalty area -- a critical area where the defending team can be penalized with a penalty kick for certain fouls.

If your knee hurts when kicking a soccer ball, patellofemoral joint syndrome is the likely cause. PFJ is quite common in soccer players, according to the Physiotherapy Sports Injury Clinic. Knee pain also can result from an anterior cruciate ligament injury, a meniscus tear or bursitis in the affected knee.