Lactate Testing is quickly becoming the preferred test for people that want to assess their aerobic capacity and determine how to make the most of their exercise program. I began to offer lactate testing to all of my patients in 2009 and I have found it effective not only for athletes but also for anyone that wants to take a more precise, deliberate approach to their exercise program.
Testing blood lactates is a relatively new practice in sport that has become popular in the last 10-20 years, especially in sports such as swimming, rowing, speed skating and endurance sports like marathons, triathalons, cycling, etc. At first, even the best trainers in the world were often confused with the use of lactate testing, but over the last 10 years, some consensus seems to have been reached on some topics and experts agree that lactate testing is a superior tool for 3 key purposes:
1 – Measurement of Endurance Performance:
Traditionally the preferred performance test for endurance activities has been the VO2 max test. A drawback to the VO2 max test is that it assesses aerobic power at a maximal intensity over a short period of time – this is not reflective of a true endurance activity which requires a longer duration of activity at a submaximal effort. Other downsides to VO2 max testing is that it can be very expensive (good equipment is very costly) and the devices used to breath in and out of can cause anxiety and discomfort in for the athlete. Aside from the minor discomfort of finger tip blood sampling, lactate testing suffers from none of these drawbacks, and is probably a better performance indicator at submaximal efforts.
2 – Assessment of changes in aerobic fitness over time:
The lactate test measures your lactate levels at many different levels of exertion. As you become more fit, your lactate levels will be lower at each of these individual exertion points; the test demonstrates that you are doing the same amount of work at lower intesities than before. This shift in lactate levels over time is a very sensitive indicator of training adaptation.
3 – A tool to opimize training intensities:
Because lactates can be used to estimate your intensity levels during exercise, it is probably the best method to determine and prescribe future training intensities or ‘training zones’. This is especially useful for fitness professionals so they can avoid overtraining or undertraining an athlete. Learning your ‘Lactate Thresholds’ can essentially make your training more specific to your goals. Whatever your goals, lactates can be used to help get reach them quicker; you can more precisely improve your endurance, your V02 max, your ability to heal and recover, or your ability to burn fat during a workout.
In his book, “The Science of Winning”, Jan Olbrecht talks about how he uses the lactate tests with elite athletes prior to big events in order to properly balance their aerobic and anaerobic systems. Although this use is less popular, it is very enticing; it is hard to argue with the 40 olympic medals that Olbrecht was part of in the Athens Olympics!
Understanding Blood Lactate
Lactate is a byproduct of glucose, or ‘sugar’ in your body. As lactate accumulates during exercise, we can assume that you are using glucose as an energy source. As the intensity of an activity increases, the percentage of energy that comes from glucose will increase, and you will produce more lactate, which can be measured in the blood. At low intensities of exercise, your body uses its aerobic energy systems (using oxygen for energy) which spares glucose and keeps lactate levels low. The more aerobically fit you are, the harder you can push yourself without accumulating lactate. Over time, as you become more aerobically fit, you will be able to achieve higher levels of intensity and keep your lactate levels the same. If we graphed this over time, your lactate curve would shift downwards, and to the right.
As you increase your intensity during exercise, you will eventually overwhelm your body’s ability to recycle or remove lactate from the blood. The highest intensity at which you can create lactate in the body and still remove it from your blood is called your lactate balance point. This is an important intensity to learn, and it has many other names; ‘anaerobic threshold’, ‘lactate threshold’, or just ‘threshold’ are the other most common names used. As you push yourself beyond this intensity, your body’s energy systems will actually become inhibited and your performance will suffer if you hope to perform much longer than 5-8 minutes. Getting to know this balance point is critical for everyone, not just athletes, exceeding your balance point in training could have negative effects to your health, your performance or even your ability to lose body fat.
How Lactate Testing is Done
So what does a blood lactate test look like? The most widely used method involves an endurance test that has incremental increases in intensity. Each stage can be anywhere from 2-5 minutes, and at the end of each stage a small blood sample is taken by a fingerprick and placed into an analyzer. The total test length can vary anywhere from 20-60 minutes, depending on the fitness of the athlete and the length or increments of the stages. Testing is usually performed on a bicycle ergometer or a treadmill. As stated previously, the test is approximating intensity at all stages, and so it does not require the participant to go ‘all out’, but it does require the participant to go up to at least an 8 or a 9/10 on the exertion scale.
Becoming more popular is the FACT method, which involves an initial staged performance test as outlined above and then follows that up with a another staged approach that is thought to better isolate the balance point between lactate production and removal from the body. I utilize both methods, as I find the traditional method effectively demonstrates fitness adaptations over time and the FACT method is excellent for determining future training intensities or ‘training zones’.
Set Your Targets and Optimize Your Training Time
After your lactate test, you will have objective information from which you can set future targets for improvements. You will also have an outline of your individualized training zones that you can use to effectively target your weaknesses and make the most of your limited training time.