05/20/2025 There are many reasons (*[whys](https://www.mayoclinic.org/healthy-lifestyle/fitness/in-depth/aerobic-exercise/art-20045541)*) to improve Cardiovascular Fitness, but in this article I'm going to focus on the *How*. In order to understand the Cardiovascular Fitness, we need to have a basic understanding of the 2 primary types of human [cellular respiration](https://en.wikipedia.org/wiki/Cellular_respiration) (the way our bodies produce energy). | Respiration Type | Byproducts | | :---------------------------------------------------------------------------------------------: | :-----------------------------------------------------: | | Aerobic Respiration (Energy Production that requires Oxygen and produces more energy) | CO2 (Carbon Dioxide, what we breathe out) & H2O (water) | | Anaerobic Respiration (Energy Production that does not require Oxygen and produces less energy) | Lactic Acid (which turns into Lactate) | Lactate is constantly produced by the body. It's only when it's production rates exceed the body's ability to clear it that noticeable levels build up (the different points of this lactate build up are called [Lactate Thresholds](https://en.wikipedia.org/wiki/Lactate_threshold) ). The more cardiovascular-ly fit we are the: 1. Less lactate we produce 2. More efficient the body becomes at clearing lactate ## How to Produce Less Lactate: This is done by increasing your body’s capacity to produce aerobic energy. What this looks like is doing longer easier cardio sessions. If you’ve never done cardio before, a long training session could look like doing a 20-30 minute walk. A good rule is when doing this type of training, you should be able to have a conversation, but it should be a little challenging. This training occurs between 60-70% of your max heart rate (zone 2, below your Lactate 1 Threshold: Aerobic Threshold). ## How to Clear Lactate more Efficiently: In order for your body to get more efficient at clearing lactate, it needs to be exposed to large amounts of lactate. High intensity interval training ([HIIT](https://en.wikipedia.org/wiki/High-intensity_interval_training)) is an example of this. You push your body hard for a period of time and then you do something less intense and repeat that process. An example of this could be sprinting for 30 seconds and jogging for 1 minute, then repeating that. Your heart rate during this training should reach between 80-90% of your max heart rate (zone 4, above your Lactate 2 Threshold: Anaerobic Threshold). ## Heart Rate Zone Training (80/20): It’s best to focus 80% of your training on longer aerobic (zone 2) cardio training (reducing lactate production) and 20% on anaerobic (zone 4) training (lactate clearance training). This is a simplification, but your aerobic (zone 2) training happens at 60-70% of your max heart rate and your anaerobic (zone 4) training happens at 80-90% of your max heart rate. Your maximum heart rate is the top limit to the amount of times your heart can beat per minute. An easy way to calculate this is by subtracting your age from 220. So if you’re 30 years old your max heart rate should be about 190 bmp (beats per minute). Again, this is a simplification. If you’d like a more detailed understanding of heart rate zones and lactate thresholds, check out [this](https://matthewboydphysio.com/running-heart-rate-zones-101/) article by [Matt](https://www.instagram.com/matthewboydphysio/) (the below picture is from it). The easiest way to track your heart rate is with a smart watch, although a chest monitor is more accurate.![[Training-Zones-Images-7-768x432.png]] --- Email any questions, or comments to [email protected]. You can also find me on [Instagram](https://www.instagram.com/thegregleopold/), [YouTube](https://www.youtube.com/@thegregleopold), and [X](https://x.com/thegregleopold).