Don't guess - test!
Once VO2Max, VLaMax, AT, and ideally, a metabolic profile are established, we can interpret these data to create personalized training zones. Interpreting test results involves analyzing various physiological markers like heart rate, RPE, breathing patterns, lactate levels, and fat oxidation profiles. These insights help understand an athlete's response to different exertion levels and their endurance capabilities.(Note: obviously our at home test is based on assumptions too but is still more accurate than a 20min FTP test. The gold standard is the lab!)
Post test - Setting the zones
Interpreting test results involves analyzing heart rate, RPE, breathing patterns, lactate (measured or calculated), and fat oxidation profiles to understand how an athlete’s body responds to different levels of exertion. These figures provide a visual representation of how physiological markers change across different training zones, offering valuable insights into an athlete’s endurance capabilities.
The first chart down is the metabolic chart that tells us about our carb & fat utilization. The point of maximal fat utilization is easy to find: the local maximum of the red curve in this case. Note that there is a significant use of carbohydrates as well which let's us conclude that energy systems have crossover zones and are not strictly separated. In short: Fuel the work accordingly and still fuel with a little amount of slow carbs during the easy rides especially if you are moving your body for long hours.
Next up we take the lactate production and find inflection points. The first marked one on the left is our aerobic threshold, which can usually be found around 1.0 -1.2 mmol/L this also often aligns with our ventilatory threshold 1. The point where we go from relaxed nose breathing to slight mouth breathing. For our example this also aligns or is close to fatmax. I usually recommend looking at the heart rate and power values that align with this point and use them as the upper limit for our easy / endurance training sessions. By targeting this zone, athletes can increase their fat-burning capacity, which is especially valuable for endurance sports where energy conservation is critical. This zone also targets type I (slow-twitch) muscle fibers, which are more efficient at using oxygen to generate ATP for continuous, extended muscle contractions over a long time. These fibers have a high number of mitochondria, which play a key role in endurance capacity. Here we also improve the efficiency of the cardiovascular system, enhancing the delivery and utilization of oxygen by the muscles. Over time, this leads to a lower heart rate at a given power output, indicating improved aerobic fitness. The body becomes more efficient at maintaining moderate activity levels without tapping into anaerobic energy systems that deplete glycogen stores and lead to quicker fatigue.
A note on lactate: Lactate is a byproduct of glycolysis and is inversely related to fat oxidation. Fat usage typically peaks near the aerobic threshold and decreases toward the anaerobic threshold, with variation among athletes. Athletes with a strong metabolic base can maintain higher fat oxidation rates, whereas those less trained or often working at higher intensities might see a sharp decrease in fat oxidation past the aerobic threshold.
And this leads us to the anaerobic threshold (AT) which is the inflection point at which lactate accumulates in the bloodstream faster than it can be cleared. It's a pivotal point where the body shifts from predominantly aerobic energy production to greater reliance on anaerobic processes, leading to increased lactate levels. Training at this threshold can enhance the body's lactate handling, delaying fatigue and improving endurance performance. It's a crucial marker for athletes, indicating the sustainable upper limit of exercise intensity for prolonged efforts.
Usually the ventilatory threshold 2 (where we switch from mouth breathing to oxygen deficiency and heavy breathing. This occurs shortly after/around the anaerobic threshold (AT). A good easy marker for us to notice what's happening if we don't have a computer in front of us. In the following graph you can easily see what's happening: we can't keep up with the oxygen demand of our performance! Hence a lot of people are emphasizing high Vo2Max as a good marker of performance, which is true. But efficiency beneath Vo2Max is just as important and a lot of the best professional athletes have a high AT in comparison to their Vo2Max ( marked as AT at % VO2max in our test).
Using this information to set individualized training zones
Okay now that we start to understand what's happening in our system we can put together our personal training zones. These will help us to improve our limiters. There are a lot of different training zones out there and every coach has their own little approach (Often because they have a certain kind of athlete they work with. I'm more endurance based therefore I focus on markers that will drive aerobic performance, metabolic efficiency and slow twitch fiber development. The good old triathlon, cycling and marathon stuff.)
Recovery: Mostly used for lactate reduction after workouts for better adaptation and better recovery for the next day
|
Easy Aerobic: The heart works steadily, enhancing blood flow and oxygen delivery to muscles, which supports the development of the cardiac muscle itself, leading to increased stroke volume and efficiency over time. Lactate production remains low in this zone, staying under 1.2 mmol/L, which means the body can effectively use and clear lactate without it accumulating. This is an indicator that the body is relying predominantly on aerobic metabolism for energy, with fatty acids serving as the primary fuel source. Training here improves the body’s ability to oxidize fat, thereby conserving glycogen stores for more intense efforts. Mitochondrial density within muscle cells also increases as a response to Easy Aerobic training. Mitochondria are the powerhouses of the cell, and their enhancement leads to better energy production, particularly the ATP generated through aerobic pathways. This is essential for endurance athletes, as it means they can perform longer without fatiguing, making the Easy Aerobic zone a cornerstone for building a robust aerobic base. It's this foundation that allows for sustainable performance and is crucial for the long-duration events that endurance athletes typically engage in. |
|
Steady Aerobic: You should use the Steady Aerobic zone when the goal is to push the aerobic system slightly harder without overreaching into high-stress anaerobic efforts. It's ideal for improving endurance and aerobic capacity, making it a suitable choice for building fitness while still allowing for relatively quick recovery. This zone is beneficial for athletes who have already established a solid aerobic base and are looking to increase their pace at a sustainable heart rate, bridging the gap between easy efforts and more intense threshold work. |
|
Sweetspot: The body starts to produce lactate at a higher rate, but the intensity is carefully managed so that it doesn't cross the lactate threshold where it would begin to accumulate rapidly. The body becomes more efficient at processing and using lactate as fuel, improving its ability to sustain higher intensities for longer periods. Training in the Sweet Spot can lead to an increase in mitochondrial density and capillarization in the muscles. More mitochondria mean greater aerobic energy production capabilities, while more capillaries improve oxygen and nutrient delivery to the muscles and facilitate waste removal. This enhances endurance and delays the onset of fatigue. |
|
Threshold: The body's lactate production meets its lactate clearance rate, resulting in an exercise intensity that can be sustained for an extended period, usually up to an hour (depending on your pacing stability). This zone is typically where an athlete's heart rate is high, and they might experience a burning sensation in their muscles due to the accumulation of lactate and hydrogen ions, but it's still manageable. Training at this threshold has several key benefits: It enhances both the aerobic system's efficiency and the anaerobic system's capacity. The body becomes better at processing and clearing lactate, which translates to improved endurance and the ability to sustain higher intensity efforts. There's an increase in stroke volume and cardiac output as the heart becomes stronger and more efficient. Muscles adapt to handle higher levels of acidity, which can improve performance in sustained, high-intensity efforts. The body increases its ability to utilize carbohydrates efficiently, which is vital for high-intensity performance. Threshold workouts are demanding and require a balance with lower-intensity sessions to avoid overtraining. They are best used when an athlete has a solid aerobic base and seeks to improve race-pace efforts and time trial performances. |
| Vo2Max: This zone propels athletes into their highest oxygen-consuming state, with efforts that are short but intense, typically lasting between 4 to 6 minutes. This zone is marked by peak heart rates and lactate levels well above the lactate threshold, signaling that the body is operating at its maximal aerobic output. The benefits of VO2Max workouts are substantial: they boost the body's oxygen uptake (but don't think you can skip the aerobic base training because that's where most of the benefits come from), maximize cardiac output, improve lactate tolerance, and enhance mitochondrial function and efficiency. Additionally, they recruit fast-twitch muscle fibers, crucial for speed and power but also very inefficient in terms of carb utilization. |
I hope this helps you to understand that training zones are not just some weird number but that they are based on your personal markers! Be smart!
https://www.konaendurance.com/
Flo