Soccer requires both anaerobic and aerobic conditioning in order to achieve optimal physical conditioning. The anaerobic system helps athletes dispense enough energy to do continuous sprints throughout the game, while the aerobic system helps athletes recover from the on going rest and restarts that soccer requires. It is important for soccer athletes to be well conditioned in both anaerobic and aerobic systems.
In order to train he anaerobic system the athlete must do an abundance of sprint training at least three times a week at maximum speed and decent form. Sprinting also helps activate the fast twitched muscle fibers in our legs. These fast twitch muscle fibers help the athlete produce power and strength and our designed to grow physically (muscle), unlike slow-twitched fibers which we will go over in the next paragraph.
Aerobic training on the other hand activates slow twitched fibers, and helps condition our cardiovascular system. Unlike anaerobic, aerobic requires that the athlete run for long distances in order to better condition the lungs to perform the non-stop moving, I say moving because soccer players aren't always running, that soccer players require. Aerobic training should be done on alternate days to your anaerobic training.
In order for soccer players to achieve optimal levels of stamina they must train both anaerobic and aerobic systems equally. Having to much or to little of either is not good for soccer players and will create unwanted athletic imbalances. A player who only runs long distances, and neglects sprint training, will have an excess of slow twitched muscle fibers and therefore lack power and speed. On the other hand, a player who only sprints will have more than sufficient fast-twitched muscle fibers, but wont be able to constantly perform feats of power and speed because of their limited lung capacity. It is highly important to be well conditioned in both to be a perfectly balanced soccer athlete. If you want more information and in depth soccer exercises and programs visit this website, and take a look at there comprehensive e book which goes deep into soccer specific workouts.