Welcome to Part Two of our lactate threshold testing. To recap a little: I (Lauren) was recently a test subject for our blood lactate threshold testing because I was entering a marathon training block after quitting my statin medication use. The statins damaged my muscles and I was trying to find speed endurance again.
In this second blog, I will show you all three results of my testing and see how and why things trended the way they did. PLUS, I will show you how wearing super shoes on my fourth test affected blood lactate and pace.
Let's briefly touch on what lactate is again (Read Part One).
What is lactate and lactate testing?
Blood lactate is a measurement of the amount of lactate (aka lactic acid) in your blood. Lactate is a byproduct of the body's metabolism and exercise, and is produced in muscles and red blood cells when the body breaks down food for energy.
A blood lactate test measures the concentration of lactate in your blood. Typically, blood is drawn by a prick on the end of your finger. The purpose of the test is to determine two thresholds, your aerobic threshold and lactate threshold.
Aerobic Threshold (AT)
This is typically defined as when the body starts to require more than just oxygen to produce energy to move. This is where the body starts to transition from using fat as a fuel source to carbohydrates. Blood lactate level should be around 2mmol. Improving this level will help you go longer and farther, which means you can go at a higher intensity for longer.
Anaerobic Threshold (AnT)
This is the tipping point where the body begins to accumulate too much lactate and additional waste byproducts cannot be cleared. Blood lactate should be around 4mmol for this level. Since this level is a tipping point, training slightly below this level can help improve adaptation in lactate clearance.
How to time your blood lactate testing
These tests are repeated three times, roughly four weeks apart. My testing was four weeks into a new marathon build, followed by another test four weeks later, and my last test was five weeks after my last test and one week before my marathon.
We added a fourth test one week after my third, and final, true lactate testing. The fourth test was performed in super shoes (Alphaflys 3). Performing this test only one week apart ensured that I did not get any fitness gains between my last test and this test. In fact, this fourth test was 2 days after a tough 18-mile run.
Test Results 1, 2, & 3
Test 1 AT:
Approx. Aerobic Threshold (2mmol) : 9:08min/mile
Recommended Training Range: 9:08 - 9:56min/mile
Test 1 AnT:
Approx. Anaerobic Threshold (4mmol) : 7:42min/mile
Training Range : 7:42 - 8:00min/mile
Test 2 AT:
Approx. Aerobic Threshold (2mmol) : 8:40min/mile (9:08min/mile)
Training Range : 8:40 - 9:40min/mile (9:08 - 9:56min/mile)
Test 2 AnT:
Approx. Anaerobic Threshold (4mmol) : 7:30min/mile (7:42min/mile)
Training Range : 7:32 - 7:50min/mile (7:42 - 7:57min/mile)
Test 3 AT:
Approx. Aerobic Threshold (2mmol) : 8:35min/mile (8:40min/mile) (9:08min/mile)
Training Range : 8:35-9:40min/mile (8:40 - 9:40min/mil) (9:08 - 9:56min/mile)
Test 3 AnT:
Approx. Anaerobic Threshold (4mmol) : 7:27min/mile (7:35min/mile) (7:42min/mile)
Training Range : 7:27-7:50min/mile (7:32 - 7:50min/mile) (7:42 - 7:57min/mile)
What do these Aerobic and Anaerobic Ranges mean when it comes to training?
Training Recommendations: While it is beneficial to know these numbers, remember that they can vary from day to day, depending on stress, sleep, hydration, nutrition, etc, so don't take the exact numbers too seriously. It is better to slightly train a little below these numbers than to go past them. By training near these levels, it will help shift this curve to the right which means that for faster paces, you will have lower blood lactate levels.
Training AT: When training at or slightly below this AT, you can see improvement in your overall fitness over time. Running close to this threshold will help set up your marathon, especially when you are early in your build. It can be beneficial to run a couple of runs a week at this pace, either for a portion or its entirety. It can be beneficial to have a portion of your long run done at this pace. Remember to listen to your body and not push too hard, especially if you are not used to doing this. Gradually increase your duration at this pace during the long run and increase the duration as you feel comfortable.
AnT: When training at or slightly below your AnT, this can help raise your aerobic levels, running economy, lactate capacity, clearance, and buffering.
Summary of Tests 1-3:
As you can see, there is a total shift in the curve toward the right (meaning faster paces for similar blood lactate levels) from the first test to the second and third tests. For example, both AnT and AT improved between tests one through three. The difference between the second and third shows a shift in the AnT, while the AT remained the same.
The improvement in fitness can be attributed to spending time training the appropriate levels (recommended training ranges) of both AT and AnT for current fitness levels.
Super Shoes/Test 4:
A repeat of the blood lactate test was completed with super shoes 7 days after the third test. This was done to compare the effect super shoes had with minimal impact on fitness gains/losses.
Super Shoes Test 4: Approx. AT (2mmol) : 8:35min/mile (8:35min/mile),(8:40min/mile),(9:08min/mile)
Super Shoes Test 4: Training Range : 8:10-9:10min/mile (8:35-8:40min/mil), (8:40-9:40min/mile), (9:08 - 9:56min/mile)
Super Shoes Test 4: Approx. AnT (4mmol) : 7:27min/mile (7:35min/mile), (7:30min/mile), (7:42min/mile)
Super Shoes Test 4: Training Range : 7:18-7:45min/mile (7:27 - 7:50min/mile), (7:30 - 7:50min/mile), (7:42 - 7:57min/mile)
How do super shoes affect training and recovery?
It can be seen that there is a shift in the curve between the third and fourth tests. This would indicate that super shoes aid in performance outside of training adaptations. In other words, for the same lactate levels you can run at a faster pace. For example, at 8:22min/mile lactate levels were measured at 1.8mmol with super shoes. In test three at 8:22min/mile lactate levels were measured at 2.1mmol in regular trainers.
This has much to do with why super shoes were invented and the reason there continues to be new development with plated shoes and lightweight energy-returning foams. The impact of having a shoe that returns energy more efficiently means that less energy is required on muscles to produce the forces necessary to maintain a certain pace. It is important to note the difference in paces so that the appropriate levels are being trained.
One of the adaptations in training near AnT is the ability to increase lactate capacity. It can be seen that there is a slight difference in both pace and blood lactate concentration between the third and fourth tests. Lactate levels while wearing super shoes were 7.4mmol for 6:46min/mile pace while lactate levels were 6.5mmol for 7:00min/mile pace. This is interesting to see and may warrant further investigation. Is it possible that using super shoes allows the body to handle more lactate, due to the aid in mechanical efficiencies? This might be a topic for another blog for another day!
Conclusion
Lactate testing to find key thresholds (aerobic and anaerobic) can be useful knowledge to have for training. It can help define and narrow, what paces and effort levels to train at for adaptation. Whether you are someone who is looking to PR your next race, or a beginner first starting out, knowing your threshold training levels can help guide you to improve over time.
The use of super shoes should be seen as a way to improve performance for short-term gains.
Summary
Knowing your lactate threshold lets you train with more precision. Many coaches prescribe some running at the lactate threshold as part of an overall training program. Also, it is a main indicator of how well you are training and how fast you are able to run a marathon or half marathon.
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