Is soccer an aerobic or anaerobic sport?

There have been many debates on how to train soccer players for years. Traditional theorists insist that it is important to do long runs for over an hour to build up the aerobic system. Others use a series of longer sprints to work more of the anaerobic system. When watching a soccer match, you will see that for a majority of the time, the players are jogging and even walking, which supports the conclusion that they are in their aerobic system most of the time. The problem with training for soccer using only aerobic conditioning is that when the players have to do a series of sprints during a game their bodies have not been trained to perform for these anaerobic demands. If the player has not trained this anaerobic system correctly, they will start to fatigue quickly.  This means that while soccer is an aerobic sport, the players' performance will be limited by how they respond to anaerobic demands. As a result, you will need to train so you have a good aerobic base and also complete intervals at a high intensity to raise the anaerobic threshold. Long runs outside of practice are not typically needed since the intensity and length of the practices should provide the aerobic work capacity that long runs are meant to develop. However, you will need to add short sprint training at high anaerobic levels a couple times per week to make sure your anaerobic system is ready for any demands the game might bring.