Workouts to Improve Lactate Clearing Rates


March 31, 2011

Ask most runners what causes fatigue, and the answer is almost always lactic acid, or its scientific cousin lactate. The mere mention of the word conjures up memories of intense pain, struggle, and the infamous butt lock during the final stretch of a race. Contrary to popular belief, however, lactate is a runner's friend, not foe. Instead of being an evil substance that causes the elephant to jump on your back in the finishing stretch of a race, lactate is a key fuel source when you run fast.

What gives lactate its bad reputation? As you run faster, your rate of lactate production and consumption rises, but as a well-trained runner, you can "clear" the lactate as quickly as you produce it. At some point, however, either because of running faster or because of holding a fast pace for too long, you produce more lactate than you can clear from your bloodstream. When this happens, the hydrogen ions associated with producing lactate turn off the enzymes used to produce energy and may interfere with your uptake of calcium. As a result, your muscles' ability to contract is reduced and you're forced to slow. In other words, all the sensations commonly associated with "lactic acid" appear when you can no longer process lactate as quickly as you produce it.

Tempo runs and cruise intervals are the traditional training means to address this issue. By improving your ability to clear or tolerate lactate as it's increasingly produced, these training strategies allow you to sustain a faster pace for longer. While conventional tempo runs and cruise intervals work fine, elite coaches and Kenyan athletes have added a new wrinkle that may help runners increase the use of lactate during a race and therefore help clear it and all the corresponding fatiguing products out much quicker.


Renato Canova, an Italian coach who works with many of the world's best runners, believes one factor that sets East African runners apart is that they're better able than their Western counterparts to clear lactate at race speeds. Most runners are able to clear lactate quickly at speeds up to threshold or tempo speed, or somewhere between 15K and half marathon race pace; faster than that, our clearing mechanisms are overwhelmed and there's an increasing stream of lactate pouring into our blood.


To get around these shortcomings, two workouts can be used. Both work on the principle that instead of keeping lactate steady, it should undulate, meaning that a segment of faster running to increase lactate production should be followed by a slower segment that allows for clearance of the previously produced lactate to take place.

The first method is what Canova calls alternations. Alternations consist of a continuous run where segments of slightly faster running are alternated with periods of slightly slower running. For half marathon and shorter races, the goal is to have one segment at race pace and one slightly slower than a traditional tempo pace. A good rule of thumb is to begin the season with the slower segment at 20 to 40 seconds per mile slower than your normal tempo run pace. Over the course of the training period, gradually speed up this segment so that the gap between the paces of the two segments decreases. When training for the marathon, race pace should be alternated with a pace that's initially 15 to 20 seconds faster per mile, as this will train the body to use lactate as a fuel source at marathon pace.

Detailed below is a progression through a series of alternations leading up to a half marathon.Half Marathon Alternations Progression

In the 10 weeks leading up to a half marathon, do this series of workouts to improve your ability to clear lactate at race pace.
HM = half marathon goal pace per mile.

10 WEEKS TO GO: 6 miles alternating 400m at HM +5 seconds/mile with 1200m at HM +40 seconds/mile

8 WEEKS TO GO: 7 miles alternating 600m at HM with 1,000m at HM +35 seconds/mile

6 WEEKS TO GO: 7 miles alternating 800m at HM-5 seconds/mile with 800m at HM +35 seconds/mile

4 WEEKS TO GO: 8 miles alternating 1,000m at HM-10 seconds/mile with 600m at HM +30 seconds/mile

2 WEEKS TO GO: 8 miles alternating 1,000m at HM-10 seconds/mile with 600m at HM +20 seconds/mile