Training the Body to Use Lactate as a Fuel
No molecule in the human body gets as bad a wrap as lactate. Better known to athletes incorrectly as lactic acid, the molecule L-lactate is constantly produced from pyruvate in the body as it attempts to extract all the potential energy stored in glucose. A byproduct of the utilization of the derived ATP from this process is what creates the acidic environment in the exercising body due to the accumulation of hydrogen ions. The lactate molecule and hydrogen ions are two of the many biochemical reactions that take place in the body unnoticed, until it's in an endurance athletes body and they are working at a steady state of exercise. Then byproducts of energy production, lactate and hydrogen ions, can accumulate in the blood stream as they diffuses from muscles. This will lower the blood's pH and increase the amount of lactate in the blood. Lactate then hitches a ride with red blood cells and may visit the liver or heart, where assuming oxygen is present in sufficient quantity, it can actually be created into usable energy for the working body. The higher the rate of work, the more the system can be backed up and lactate and hydrogen ions will remain in the blood stream in greater quantities. Knowledge of this process allows us to test the working levels of blood lactate at various training paces as described in part I of this article. We can then use these levels and corresponding intensities to train the body to work more efficiently at ever greater workloads. This allows us to produce greater aerobic power and perform to our best capabilities.
Training to specifically improve our lactate recycling capabilities can come in the form or two types of training.
Lactate Threshold Training
The first type of training is best described as 'Lactate threshold training'. Lactate threshold training aims to increase the level of blood lactate above resting or moderate exercise levels (1.5-4.0 mmol/l in most athletes) and keep the work level or in 'steady state' so the body can develop it's ability to recycle lactate through the blood stream and offset the potential for acidosis by the accumulation of hydrogen ions. This type of work can be done in various workout formats. I have developed a list of workout ideas below entitled 'Lactate threshold workouts'.
Anaerobic Capacity Training
A second way to improve the body’s ability to utilize lactate most efficiently is to perform training best described as 'Anaerobic capacity training'. This type of training is deemed 'anaerobic' because it primarily utilizes anaerobic metabolism which can produce energy independent of the presence of oxygen. This is valuable training for endurance athletes for a variety of reasons. For one this anaerobic capacity training can be thought of as running strength training. This is because its intensity (100-120% of VO2 max or 400m-800m race pace) is so high that it requires the runner to use new motor units (small groups of muscle fibers within a larger muscle group). Activating new motor units and building new neural pathways is the way you develop the strength you gain when in the gym lifting free weights. For runners this strength 'gain' translates into better running efficiency at a variety of paces. That is to say that it takes less muscular energy to run at the speed the anaerobic capacity training is done at and paces slower than it because more power is now generated with each stride. The second benefit is in the adaptations the muscles undergo in the environment flooded with lactate. Because the energy is being derived from the complete catabolism of glucose to lactate the working muscles are flooded with lactate for a short period of time resulting in a greater ability of the muscles lactate receptors to respond to this high lactate environment while working. See my suggestions for anaerobic capacity workouts below.
Keep in mind that neither of these types of training are advisable nor fully beneficial to the athlete if a proper base of training has been set to develop the aerobic energy system and oxygen transport throughout the body. 6 or more weeks of comfortable paced running is needed to develop the infrastructure in the body to make the workouts below useful to you.
Lactate Threshold Workouts for Runners
Workout I - 2-4 x 2000m with 90 seconds rest in between. Each of these runs should be done at your established lactate threshold pace. Strict adherence to the 90 seconds rest is a must for a full benefit to the workout. If it takes you 9 minutes or less for each 2000m run you can do 3 or 4. sets If longer than 9 minutes begin with 2 sets. Ex: A runner with a lactate threshold pace of 6:30 min/mile would run 3 x 2000m at 6:30 pace with 90 seconds rest (8:07 for 2000m).
Workout II - 3-5 miles at steady state pace. This is a continuous run done after a proper warm up. This should be done at an intensity slightly below the estimated lactate threshold pace due to its continuous nature. Reducing the lactate threshold pace by 3-5% is appropriate. Select the distance you will run based on your estimated time run. Do not run for more than 25 minutes. Therefore: a runner who has been tested as having a lactate threshold pace of 5:30 would run 4 miles at 5:46 (5% slower).
Workout III - a 45 minute continuous run performed in a progressive manner. This means the athlete would begin the workout at a pace corresponding to the first rise in blood lactate from there test. This is often marathon race pace for runners or a bit slower. They will hold this pace for 20 minutes. The pace is then increased about 5% for 15 minutes. Finally the last 10 minutes of the run are done near the lactate threshold pace (another 5% increase in pace). There is no rest taken during this run, therefore it is quite challenging and is recommended for experienced racers. Runner can also use race that will take 45-60 minutes to complete to obtain the same training benefit.
Anaerobic Capacity Workouts for Runners
If beginning anaerobic capacity training it is advised to focus on the quality of each run by performing shorter intervals to begin with and taking as much recovery as needed to perform an equal effort on each.
Workout I - 6-10 x 200m with 2 - 3 minutes rest. Each of these runs should be done quite fast. The pace should be akin to one you would use if you where to race a 400-800m run. Since many runners have never explored racing those distances, it can also be described as very fast, but not "top speed."
Workout II - 8-12 x 100m hill (8-10% grade) with 3 minutes rest. Find a moderately steep hill and run up the hill fast with good form. Make sure to take a full recovery (up to 3 minutes and no less than 2 is recommended) so your performance is equally high on each repetition of the hill.
Workout III - 4-8 x 400m with 3 minutes rest. The intensity is equal to workout I and therefore this is more challenging due to is length. This is recommended for experienced runners.
Training the body to utilize its "diamond in the rough" of energy sources is a straightforward process once you have accurately established your OWN lactate threshold. It can lead to an improvement in aerobic power which is the functional element most predictive to success in endurance competitions. Knowledge of your lactate threshold pace allows your training to become focused and the benefits of your training to be realized more quickly. Furthermore an educated coach can use your lactate profile to develop a periodized training program that improves your areas of weakness and improves your aerobic capacity for your goal event.
I will be conducting a weekend of lactate tests for multisport athletes using their bikes and a CompuTrainer. This test will provide cyclists and multisport athletes the intensities and heart rate training zones appropriate for them to use for their aerobic and anaerobic training. To inquire about availability of the test, click here.
I encourage you to find out the specific intensities you should be training at even if you don't have the ability to take part in one of my lactate tests. My race performance calculator will provide you with recommended training paces based on a recent race performance and estimate heart rate from age and resting heart rate. You can find this valuable calculator here.
Long may you run,
Sean Coster
Complete Running Programs offers lactate threshold performance tests for runners and cyclists of various abilities. For more information check out this information on lactate testing.
For more writings on training, motivation and philosophies in distance running visit Sean's blog at www.seancoster.org/runningportland or www.crpusa.com
Copyright 2008 Complete Running Programs - May not be used without permission of the author.
