Anaerobic metabolism produces energy for short, high-intensity bursts of activity (lasting no more than a few minutes) before the lactic acid build-up reaches a threshold where it can no longer be absorbed and, therefore, accumulates. This point is known as the lactate threshold and is usually reached between 50 to 80% of a athlete's VO2 max.
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Athletes often use their lactate threshold to determine how to train and what sort of a pace they can maintain during endurance sports. Because the lactate threshold can be increased greatly with training, many athletes and coaches have devised complicated training plans to increase this value (LT Training).

