Magness Speaks — Workouts to Improve Lactate Clearing Rates
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.
IN THE CLEAR
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.
We tend to attack this problem by continually doing threshold or tempo runs to slowly improve our ability to get rid of the lactate. The first drawback with this method is that it does little to teach the body to clear lactate at faster race paces. The second issue is that, when doing tempo runs, lactate clearance is relatively constant so the body is never stressed to the degree that it needs to be to figure out a faster way to get it out of there.
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
The second type of unconventional workout to improve your lactate clearance is blend intervals, consisting of a "mix of long and short intervals in order to increase the ability to remove lactate quickly," according to Canova.
The method is similar to alternations except it's done interval-style, with rest periods in between. During the workout, a longer interval, such as a mile, is followed by a shorter segment, such as a quarter mile, before going back to the longer interval and repeating the sequence several times. The rest period before the shorter segment should also be relatively brief, with a longer recovery occurring before the cycle is repeated.
Blend intervals work via a slightly different mechanism, although the basic premise of the faster segment increasing lactate production and the longer segment working on dealing with that lactate remains. According to Canova, the main mechanism is that the workout "improves the permeability of the cell membrane," meaning that the lactate is better able to leave or enter the muscle.
Detailed below is a progression through a series of blend intervals leading up to a 5K.
5K Blend Intervals Progression
In the 10 weeks leading up to a key 5K, do this series of workouts to improve your ability to clear lactate at race pace.
5K = 5K goal pace per mile.
10 WEEKS TO GO: 3 sets of (2,000m @ 5K pace, 2-minute jog, 200m @ 5K-20 seconds/mile), with 4-minute jog between sets
8 WEEKS TO GO: 3 sets of (2,000m @ 5K-10 seconds/mile, 2-minute jog, 300m @ 5K-25 seconds/mile), with 4-minute jog between sets
6 WEEKS TO GO: 3 sets of (1600m @ 5K-10 seconds/mile, 2-minute jog, 300m @ 5K-25 seconds/mile), with 4-minute jog between sets
4 WEEKS TO GO: 3 sets of (1200m @ 5K-15 seconds/mile, 2-minute jog, 400m @ 5K-30 seconds/mile), with 4-minute jog between sets
2 WEEKS TO GO: 3 sets of (800m @ 5K-20 seconds/mile, 2-minute jog, 400m @ 5K-35 seconds/mile) with 4-minute jog between sets
USING YOUR NEW CLEARANCE WORKOUTS
I've successfully used both alternation and blend workouts with athletes ranging from high-schoolers up to professionals. The key is to understand how to use each in the training program.
Alternation workouts can be used throughout the training period. Early on, they're best thought of as advanced tempo runs where the slower segment takes up the majority of the run. To progress these during the season, lengthen the faster segment until it's at least equal to the slower segment in duration, as demonstrated in the alternations workout table. The goal should be to reach the point where the faster segment is equal to or longer than the slower portion during the last few weeks before your key race.
Blend workouts should be used primarily during the middle to late portion of the training period, or during the time frame when traditional intervals are used. Early on, the length of the faster interval should be only 100m to 300m, while later on the speed and length can be increased to gradually increase the stress of the workout.
These workouts should add both a valuable new stimulus for adaptation and some variety to your training. Don't throw away your traditional tempo runs or intervals; instead, try adding these new variations every other week to your training plan to give it, and ultimately your race times, a boost.