Alright squad, talk about a cliff-hanger from the last blog, huh?! We really left your heart RACING, didn’t we? Alright, enough with the puns, Dylan, nobody likes them.


Well, after losing about half of you with all the term-defining-sciencey-jargon-talk from the last blog, we’re finally getting into the good stuff! In Part 2, we’re unpacking everything you need to know about:

  • Implementing a Zone-Based Approach To Training
  • Understanding Which Models are Beneficial to Use for Zone Training
  • Different types of Zone Training for Different Athletes, AND…
  • More term-defining-sciencey-jargon-talk :/



As an athlete, weekend warrior, or just every-day exerciser looking to make improvements over time, using a Zone Based approach to your cardio training is helpful to conceptualize your overall training load for a week (load = intensity x volume). By identifying which zone(s) you aim to train in, and the time spent in each zone, you can easily track progress through intensity, duration, distance, speed, or any metric you choose! Having a repeatable method to track your cardio is always helpful to show how far you’ve come.


Now comes the fun part.



Before we delve into the intricacies of zone-based cardio training, let’s revisit a fundamental concept – the crossover point. Remember? The point at which your body shifts gears from it’s low & slow engine idling (aerobic fat metabolism) to the turbocharged V10 (anaerobic carbohydrate metabolism) that stalls out after just a couple minutes? Yeah that crossover point!


Okay, well a little more about the crossover point – this transition is actually fitness-dependent. This means the fitter you are, the LONGER your body uses aerobic metabolism to feast on fat stores before transitioning to carbohydrate metabolism. That means the more you train, the wider your range of ‘Zone 1’ becomes! (CITATION NEEDED HERE)



**Disclaimer – This blog has been written from the perspective of the 3 Zone Training model to make training theory become more approachable. Numbers may differ if you use the 5 Zone or 7 Zone models.

When it comes to zone-based cardio training, there are three main strategies:

    • PYRAMIDAL MODEL: Imagine a pyramid where the base is built with your Zone 1 training (ie low intensity, aerobic training). As you work your way up the slope, the amount of time spent in zones 2 and 3 get progressively smaller. So much so that close to 80% of this pyramid is your Zone 1 ‘Base,’ while Zones 2 and 3 fight for the remaining 20% of training volume.
    •  POLARIZED MODEL: As the name implies, this training style wants nothing to do with the ‘middle ground.’ Zone 2? Never heard of it! Polarized advocates still dedicate about 80% of their training time to Zone 1, but the other 20% is ALL for Zone 3 to take.
    • THRESHOLD MODEL: The Threshold Training Model is the antithesis of Polarized: Zone 2 takes the lead in this model, accounting for close to 35% or more of your training time, while Zones 1 and 3 play the rhythm section, sharing the remainder of training attention.



With multiple strategies to choose from, it’s only human nature for us to assume that one method will reign supreme. Lucky for us, we’re not the only ones with those thoughts.

Last year, researcher Yuri Campos and their team set out to determine how different methods of ‘Training Intensity Distribution,’ such as the three strategies from above, yielded different results in athletes. If you’re anything like me, the results might surprise you:



So… what does that mean exactly?


Well, as you may have pieced together, the Pyramid and Polarizing training models both fit that description, while unfortunately, the higher volumes of the Threshold model seem to fall behind. While the mechanisms have yet to disclose themselves, there seems to be something about spending long hours at comfortable paces, while every now and then, opening the throttle into the ‘pain cave’ to make sure you still got it.


But, don’t take it from just a bunch of research nerds in a lab… take it from the elite athletes that are pushing the boundaries of the sport! Who… also happen to be studied voraciously by a bunch of nerds… in a lab. 


Casado et al (2022), Kenneally et al (2021) AND Esteve-Lanao et al (2005) all studied world-class elite endurance athletes to understand what their training consisted of. Venture to take a guess what they found?



The best of the best spend anywhere from 70 to 90% of their training intensity in Zone 1! Pretty crazy right?! But hey, let’s hold our horses here. There’s a common misinterpretation of these findings, so let’s unpack that.



Let’s be honest, these elite athletes’ ‘Zone 1’ is probably your Zone 2, and definitely my Zone 3. As we have established, they’re FREAKS, likely with VO2max’s in the mid to high 70’s (ml/kg-min). So while they’re relative intensity of running is still considered low, their raw output is still insanely high. This brings up a very interesting point in the research…


We established in Part 1 that generally, Zone 1 is our easy-moderate zone that describes a pace that is all ‘sub-threshold’ intensity. Putting some numbers back in the mix, Zone 1, based on a 3 zone model, lives between 50%VO2max, and Lactate Threshold 1 (aka – 50-70% of HRmax). Finally, we already know that if you’re fitter, you can hold on to fat metabolism for longer; extending the window of intensity that you can label as ‘Zone 1.’


Are you starting to see where I’m going with this? If not, let’s bring the experts back in to bolster this concept.


Billat & colleagues wrote a great review of interval training for elite middle & long distance runners back in 2001. In this article the author remarks that ‘Zone 1’ for these athletes would only last 30-45 minutes in duration (per session), but their pace was at 75-80% of their vVO2max (velocity at VO2max). While there are some nuances between vVO2max and true VO2max (peak Oxygen consumption during maximal intensity exercise), we can easily see that 75-80% intensity would generally find itself much more at home in Zone 2 than Zone 1.


My main point here is this:


Just because Lebron James makes 500 shots before & after practice doesn’t mean you need to do so for your weekly pick-up game.


The greats are great for a reason, and while their training is a factor in what they are capable of, there are likely multiple other factors at play (genetics, training age, training history, body composition, etc.).



Spending 80% of your training volume in Zone 1 is likely a good place to start for multiple reasons:

  1. You’re not gassed after every run.
  2. The stimulus is easier to recover from, allowing you to accumulate MORE volume over time.
  3. It anchors you to what Low-Moderate intensity actually feels like
  4. It leaves you with enough energy to participate in resistance training 2-3x per week (a non-negotiable for runners).


But – we don’t need to use the exact parameters of how the ‘elites’ train to begin our fitness journey. Your heart rate is more than a statistic – it’s a compass leading you to personalized training. It’s a guide that can help provide feedback based on where you are now, and where you want to go.


Whether you use a Pyramid, Polarized, or Threshold based approach to your training, there’s always going to be a constant:


You’re going to get fitter.


Now, it’s just a matter of finding which model fits your style, schedule, and mentality of training best and roll with it! LEVERAGE the information that you get from the devices you use to inform your training, but don’t let the numbers consume you.


At the end of the day, are these devices even all that reliable? Are our bodies reliable enough to give us accurate information? What can we do if the data becomes misleading?


Did we just make this a trilogy?!


You bet. Keep your eyes peeled Part 3, the Finale of Zone Based Training coming soon!



Dylan Carmody is a Doctor of Physical Therapy, and Strength & Conditioning Coach with 5+ years in the performance and rehab industries.

Having dabbled in training modalities like Olympic Lifting, Cycling, Powerlifting, and CrossFit, Dylan has a deep appreciationfor all things performance, while still having a positive and fun-loving approach to exercise.

Dylan’s coaching experience is equally eclectic, ranging from performance coaching for elite athletes in the NCAA D1 setting, to group fitness and weight loss coaching in his early career.

With detailed exercise programming & consistent communication, he aims to create a training environment that is not only ‘tolerable’ for clients’ aches and pains, but truly helps to resolve their issues in the first place.



  1. Bellinger, Phillip, Blayne Arnold, and Clare Minahan. “Quantifying the training-intensity distribution in middle-distance runners: the influence of different methods of training-intensity quantification.” International Journal of Sports Physiology and Performance 15.3 (2020): 319-323.
  2. Casado, Arturo et al. “Training Periodization, Methods, Intensity Distribution, and Volume in Highly Trained and Elite Distance Runners: A Systematic Review.” International journal of sports physiology and performance vol. 17,6 (2022): 820-833. doi:10.1123/ijspp.2021-0435
  3. Campos, Yuri et al. “Training-intensity Distribution on Middle- and Long-distance Runners: A Systematic Review.” International journal of sports medicine vol. 43,4 (2022): 305-316. doi:10.1055/a-1559-3623
  4. Esteve-Lanao, Jonathan et al. “How do endurance runners actually train? Relationship with competition performance.” Medicine and science in sports and exercise vol. 37,3 (2005): 496-504. doi:10.1249/01.mss.0000155393.78744.86
  5. Jeukendrup, A, and A VanDiemen. “Heart rate monitoring during training and competition in cyclists.” Journal of sports sciences vol. 16 Suppl (1998): S91-9. doi:10.1080/026404198366722
  6. Kenneally, Mark et al. “Training intensity distribution analysis by race pace vs. physiological approach in world-class middle- and long-distance runners.” European journal of sport science vol. 21,6 (2021): 819-826. doi:10.1080/17461391.2020.1773934
  7. Lechner, Sandra, et al. “Monitoring training load in youth soccer players: effects of a six-week preparatory training program and the associations between external and internal loads.” Biology of Sport 40.1 (2023): 63-75.
  8. Physiology of training: Kenney, W. Larry, Jack H. Wilmore, and David L. Costill. Physiology of sport and exercise. Human kinetics, 2021.

Share This Article


Join Citizen Athletics

Exceptional strength and rehab programming by two strength coach physical therapists.