Lactate Threshold

I mentioned the term "lactate threshold" in yesterday's post about Yasso 800's. Although I have heard this term before and know vaguely what it is, I figured I tie down the specifics a bit. Your lactate threshold (or anaerobic threshold) is the point at which lactate begins to build up in the blood. Although lactate is produced every time you exercise, production and absorption balance out for light to moderate efforts. So, why is build up bad? Well, lactate (aka lactic acid) is an acid. When hydrogen ions accumulate in your blood, pH drops, muscle contraction is impaired, and power output drops (aka the beginning of the end). Therefore, the lactate threshold is essentially the highest constant effort that a person can sustain for a "long" (>30min) period of time. As it is a valuable indicator of fitness, it is worth knowing your "running speed at lactate threshold" (RSLT... feel like we're playing Wheel of Fortune on that acronym).

There are various ways to go about computing this metric. Although there are laboratory tests and commercially available analyzers, these can get expensive and require you to draw blood. So, your best bet is to perform one of the four field tests mentioned (i.e., the VDOT test, the Conconi method, the 3200m time trial, and the 30-min exam). Of these, the 30-min exam is apparently the most accurate, and is described in detail in the later portion of this article. #20