Training Dictionary
Lactic Threshold
Definition: The lactic threshold is the point where the body is no longer capable of removing lactate at the rate it is being produced.
Lactate (and it'd dissociated form lactic acid) is the product of muscles breaking down glucose in absence of oxygen, producing lactic acid.1
As workload is increased, a greater number of fast twitch, anaerobic muscles are recruited. Fast twitch muscles start to be utilized far below the anaerobic threshold; however, the body is capable of recycling lactate into fuel as quick as it is produced.2
Your anaerobic threshold is often identified by identifying where you reach ventilatory threshold and pass your lactate threshold.
(don't worry, we'll explain these terms and the differences in the near future)
Effects of Exercise
Both trained and untrained individuals produce lactate at the same rate. With training, an individual will be able to clear lactate at a greater rate and thus have lower lactate accumulation.2 With training, an individual will also be able to ride at a higher percentage of their maximal heart rate before reaching their anaerobic threshold.3
Important Details
Riding at or above your lactic threshold will bring you great gains in fitness but it's playing with fire if implementing it into your training without a plan
Sources:
1 Nelson & Cox, 2005. Lehninger Principles of Biochemistry. 4th Edition. W.H. Freeman and Company, New York 523 p.
2 Brooks, G. A. Training improves lactate clearance. In Membranes and Mucles, M. C. Berman, W. Gevers, and L.H. Opie. (Eds.) Oxford: RL Press, 1985, 257-275 pp.
3 Robergs & Stevens 2003. Fundamentals of Exercise Physiology: For Fitness, Performance, and Health, 2nd Edition. McGraw-Hill, New York 129 p.
