Anaerobic Exercise
Exercise of much higher intensity than aerobic work, which uses up oxygen more quickly than the body can replenish it in the working muscles. Anaerobic exercise eventually builds up a significant oxygen debt that forces an athlete to terminate the exercise session rather quickly. Anaerobic exercise (the kind of exercise to which bodybuilding training belongs) burns up glycogen (muscle sugar) to supply its energy needs. Fast sprinting is a typical anaerobic form of exercise.
compare aerobic