Varying degrees of fitness are required, depending on the player's position in the team, the amount of time spent on the field and the level at which the game is played. A full 90-minute match, for example, demands high levels of aerobic fitness.

The intermittent nature of the game means that energy demands are sometimes extremely high and sometimes fairly low; however, studies have shown that at professional levels the average work rate (based on percentage of maximum oxygen uptake) of midfield players and strikers is similar to that of a good marathon runner.

This means football players must have a good aerobic endurance base if they are to last the full game without becoming excessively tired. Because the game involves acceleration and deceleration, changes in direction, angled runs and running backwards - all unorthodox methods of running - there's also an increased energy cost of the exercise.

Goalie vs midfielder

The fitness demands of the game depend largely on the level of competition and on the position of the player within the field.

A study looking at the ground distance covered by professional football players playing in different positions estimated that goalkeepers cover about 4,000 metres during a game, whereas midfielders cover about 10,000 metres in the same time.

In addition, the sudden increase in speed as a player sprints for the ball taxes the anaerobic energy systems; that is, those energy systems that work without oxygen. Using these energy systems is very tiring - and a quick recovery from this is important to the outcome of the game.

To play football well, the player should continue to play throughout the year and/or train in the off-season as well as during the season. Running ability is important and cardiovascular fitness is best maintained with running activities.

How to get involved

Almost all towns and villages in the UK have football clubs that operate at varying levels, from social to professional. In addition, leagues are set up for the full game and five-a-side, and are organised through sports and social clubs, health clubs, sports centres, community schools and even pubs.

Where to play

One of the greatest advantages of football is that it can be played with any number of players and on any piece of land. Five-a-side games, for example, often take place in sports halls, but can also be played in the street, on the beach, or on waste ground with minimal facilities and minimal organisation.

Safety

A lack of cardiovascular endurance will reduce a person's level of play as fatigue will set in earlier. In addition, the sudden directional and speed changes involved in the game put the player at risk of joint or muscle injury, especially as fatigue becomes an issue. This can be avoided with strength and flexibility training.

Sport-specific circuits are an excellent way of training for football, as strengths specific to the game can be built into them. The circuit can also be designed to mimic the energy costs of a game.

This topic has been taken from the www.bbc.co.uk