What is Lactate and Lactate Threshold?

Lactate (often confused with Lactic acid) is commonly misconceived as a waste product in or bodies that limits performance. In reality, this substance is a form of fuel used by our body’s aerobic system. Because this substance is produced along with metabolic byproducts such as hydrogen ions, it is commonly associated with the onset of fatigue. The hydrogen ions are the culprit for the “burning sensation” we feel and not lactate. They raise our muscle’s acidity and in turn inhibit muscular contraction. Because of the close correlation between the accumulation of hydrogen ions and the onset of blood lactate, measuring one’s lactate is an excellent way of monitoring the state of our bodies.

What is Lactate Testing?

Lactate testing (not to be confused with ordinary non-invasive lactate threshold testing) is a powerful and reliable predictor of performance and endurance fitness. It tell us the state of your aerobic and anaerobic systems. It determines the point in which your body begins to produce lactate faster than it is eliminated. Lactate testing also determines appropriate training intensities/zones based on relative lactate concentration and the specific type of training one needs to improve. Monitoring the lactate curve helps assess the progress of athletes in all levels.

Testing Protocol*:

  • You will start with an easy warm up on the cycling trainer or treadmill. The bike will be hooked up to a hub based power meter to measure wattage.
  • After the warm up, you will go through an incremental step test consisting of 4 minute segments at predefined paces. Following each step, blood lactate levels are immediately measured and recorded. This test involves getting a very small blood sample from the finger for the assessment of blood lactate (similar to blood glucose monitoring).
  • The workload is increased by approximately 25 watts (bike) or 1kph (run) every four minutes. During each stage, rate of perceived exertion (RPE), average wattage/speed (Power/Pace), and heart rate (HR) are taken. Athletes typically ride/run about 5-6 stages, or until a break point/lactate threshold is identified.

*Note: Cycling and Running protocols are similar

The lactate values for each step are graphed into what we call the Lactate Curve Based on this curve, the athlete’s training zones are established. Contrary to what some people may think, peak lactate is not measured in this protocol. Rather, lactate levels that can be sustained for specific durations (ranging from a few minutes to several hours) is recorded.

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What is the difference between measuring blood lactate and non-invasive methods such as Near Infrared Spectrometry (NIRS)?

Blood lactate is the gold standard in lactate threshold testing. This time-proven system is what the professional/Olympic/elite athletes use abroad. By measuring lactate directly at its source, there is a very small chance of inaccuracy. Blood lactate concentration is the single best way to analyze one’s lactate threshold and lactate curve. Furthermore, by having several samples throughout the test, we are able to keep track of the body’s response to different intensities. Based on this, we can determine one’s specific training zones and the types of training one needs to improve.

Near Infrared Spectrometry (NIRS) uses LEDs to monitor oxygen saturation in the blood instead of measuring blood lactate directly. These systems claim that a sudden drop in oxygen saturation correlates with a rise in blood lactate. This means that the device does not measure blood lactate at all and merely estimates the threshold point. Because of this, it cannot accurately define one’s training zones; instead, it merely estimates the zones by computing in terms of percentage (similar to how one would estimate HR Training zones based on max HR). This isn’t ideal as not all zones are symmetric with one another (e.g. some people have wider endurance zones relative to their tempo zone and vice versa). Moreover, it cannot determine the strength of one’s aerobic and anaerobic systems; thereby, one cannot conclude on giving training recommendations. Since it measures superficially (above the skin), things like sweat, water, hair may interfere with its readings. Based on data they released, a percentage error of 10-15% is quite common. This is quite huge as a 10% difference already spans a zone or two. (You can read more about it here.)

Why does Lactate Threshold Matter?

Knowing your lactate threshold defines the upper limit that you can sustain (based on effort) both in training and in racing. Once you race based on your numbers (lactate testing values), you will be able to pace yourself better, ride/run within your limits before hitting the wall, and save valuable energy for hard efforts where it counts – like a sprint finish. The more work you can do before reaching your lactate threshold, the better.

The following can be acquired through a lactate test:

  • Current fitness level
  • Maximum sustainable power (cycling) or pace (running)
  • Training zones – power and pace
  • A specific plan of action to improve
  • Race strategies guided by power/pace
  • An immense amount of useful performance information such as efficiency and tips on proper form.

To sum it up, lactate testing allows you to set your zones accurately and precisely (no more wasted time due to trial and error). This means that you get the most bang for your buck for every minute spent training. By knowing what areas you need to improve on, you get to dedicate the necessary time and effort to address these weaknesses. Continuous improvement comes from a smart training program. Gathering information about your body and lactate threshold doesn’t do you much good unless you incorporate it into your training.

What are the performance benefits of getting a lactate test?

Knowing your ‘Lactate Profile’ can help improve your performance by letting you know the following:

  • Your redline or upper limit of your sustainable intensity
  • Specific and invididualized training zones
  • Current state of our aerobic/anaerobic systems
  • Underdeveloped zones
  • Correct intensities needed to avoid overtraining or undertraining
  • The types of training one would need to improve
  • Potential race times and race strategies

Knowing your lactate profile will ensure that you get to train optimally, spend your time wisely, and know where you need to set your focus depending on the event you’re preparing for to ensure you reach your peak performance.

Who should get a lactate test?

  • Athletes who are interested in training using scientific data to pinpoint their heart rate and training zones to maximize each training session.
  • Athletes who want to take their training to the next level.
  • Athletes who want to add precision to their training.
  • Athletes who want to make the most out of their limited training schedule.
  • Athletes who want to break out of a plateau
  • Athletes who want to gain an edge against the competition

At what part of my training block is it best to get a test?

It is useful to conduct the Lactate Test at the start of a training program and midway into the training cycle. Since the LT test provides you with data needed to generate HR zones and paces/power, you can repeat the LT test within the training cycle to adjust as you improve. It is also beneficial to have the test right before the key race to help fine tune one’s race strategy.

How often should I get tested?

Regular lactate testing (every 3-4 months for competitive athletes, annually for regular athletes) provides you and your coach with concrete evidence of improvement or the lack thereof in performance. Once you’ve laid down a strong foundation of aerobic work and you’ve improved your pace and power, previously determined zones may already be inaccurate. A history of lactate tests allows us to get a glimpse of changes in fitness, increased power/pace at threshold, improved recovery heart rate, etc. Keeping track of your lactate curves can also help assess what kind of training you respond to best.

The real power of lactate threshold testing comes from comparing test results over time, giving an objective means of evaluating a training regimen.

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The threshold improvement between Oct 2014 and Jan 2015

If the curve morphs into a normal curve or if it shifts to the right, we can conclude that the training block was a success. The graph above shows my athlete’s improvement over the course of a training program (using her lactate curve as a guide). Previously, she could only sustain 7.5 to 8 kph for her 10k, now, she can sustain 10 kph for the same distance. That’s 20-25% improvement within a few months of proper and intelligent training.

What will I receive from my test?

  • A graph of lactate measurements and heart rate during test
  • Lactate threshold value
  • Recommended heart rate and pace training zones
  • Feedback on how to improve your training
  • Interpretation on how effective your previous training has been up to the test
  • Confidence in your training!

What should I bring during the lactate test?

If you are getting a Bike Lactate Test, bring the following:

  • Bike
  • Bike Shoes
  • Cycling/Triathlon Uniform
  • GPS Head unit (e.g. Garmin)
  • Heart Rate Monitor
  • Water Bottle
  • Towel
  • Extra Clothes

If you are getting a Run Lactate Test, bring the following: 

  • Running Shoes
  • Running Attire/Triathlon Uniform
  • GPS Watch (e.g. Garmin)
  • Heart Rate Monitor
  • Water Bottle
  • Towel
  • Extra Clothes

If you have additional questions that were not addressed in the FAQs above, don’t hesitate to send us an email at info@flyingdonv.com

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