An intensity level of exercise above which the metabolic waste product lactic acid accumulates in the blood faster than the circulatory system can remove it. Also known as the "anaerobic threshold".
The point during a graded exercise test at which the blood lactate concentration suddenly increases; a good indicator of the highest sustainable work load the individual can perform.
The running intensity where lactic acid begins to rapidly accumulate in the blood. Also called anaerobic threshold; lactate threshold speed is your 10K race pace plus 5-20 seconds or a heart rate zone between 85-89% of maximum.