Zone 2 Training: The Long Shortcut

Summary Outline:

• The “Shortcut”
• What Is Zone 2 Training?
• Heart Rate Zone Training
• What Is Blood Lactate?
• What You Should Do

The Shortcut

Everyone wants to get rich quick, whether that’s literally with respect to their bank accounts or figuratively by having results and abundance in all aspects of life. Everyday we see individuals who try something for the first time and find out that they are amazing at it. And while those stories are attractive, magnetizing, and heartwarming, they are really outside the norm. When it comes to sports, fitness, and health, one of my mentors always loved to give us the secret shortcut to elite sports performance or really elite performance in anything. 

His advice? ‘Choose your parents carefully’ Hard work may beat talent when talent doesn't work hard, but you still need to have the talent to be the best. And training response, like anything else, is a talent-driven trait. So unless you were blessed by your parents, and even then, training rules still apply to beat the norms and standards we see in society today.

Knowing that there are no real shortcuts, why does it seem like there are so many? For our ‘Shortcuts’ series we’re going to take a look at a lot of the common ‘shortcuts’ you are likely seeing or have seen over the last 10 years and break down how short they really are.

What Is Zone 2 Training?

If you have been in the fitness space of social media at all over the last year, you have no doubt heard about the term ‘Zone 2 Training.’  Influencers everywhere are flocking to this term as a means of going against the grain of the last shortcut, which we will cover in our next ‘Shortcuts’ series, that took the fitnessworld by storm in High Intensity Interval Training (i.e. think Orange Theory Fitness).

Ironically, instead of the usual push for getting fit fast, the push is to now not work as hard but a lot longer in an effort to make running more attractive and social (things that we at RunByRyan support wholeheartedly!). This seems to also follow in parallel with the larger push for having more personal time instead of just work and may be more accepted on a mainstream level due to these cultural norms. Either way, in many cases it seems to be painted as 'the answer' to health and fitness enthusiasts.

One of the reasons that the fitness industry is capable of developing such lightning in a bottle campaigns is because of the lack of consensus of terminology and information. If you’re someone who is brand new to the scene, you might have no idea what anyone is talking about and your first question is likely: ‘What is Zone 2 Training?’ Let’s answer that question.

Heart Rate Zone Training

To understand Zone 2 Training we need to understand what the zones refer to. Heart rate training zones are often crucial to structuring training programs in long-distance running. Most commonly when someone refers to heart rate zone training, they are referring to the 5 Zone Model, ranging from very light to maximum effort, each corresponding to a percentage range of an athlete's maximum heart rate.  Sometimes in competitive cycling or in European countries they use the 3 Zone Model, but we will focus on the 5 Zone Model for now.  Training in different zones affects physiological attributes to differing degrees. The following is the most common breakdown:

Zone 1 - Easy Going (Light Effort) 50-60% of your maximum heart rate.

It's very light and comfortable, ideal for warm-ups or cool-downs.

Zone 2 - Steady and Comfortable (Moderate Effort) 60-70% of your maximum heart rate.

This is a comfortable effort used for endurance training, helping you build fitness.

Zone 3 - Pushing It (Moderate to Hard Effort) 70-80% of your maximum heart rate.

You're working harder and breathing heavier, but it's sustainable for a longer time.

Zone 4 - Challenging Yourself (Hard Effort) 80-90% of your maximum heart rate.

This is a hard effort, used for improving speed and fitness. It's challenging and can't be sustained for very long.

Zone 5 - All Out (Very Hard Effort) 90-100% of your maximum heart rate.

This is your maximum effort, used for short bursts of speed and power. It's very challenging and can only be maintained for a short duration.

To get maximum heart rate you can find a variety of different equations. For RunByRyan, we will introduce University of Texas at Austin’s Dr. Tanaka’s formula (Note: all formulas have error; you can be below or above what a formula predicts due to genetics and other factors):

‍

Maximum Heart Rate=208−(0.7×Age)

If we take a 30-yearold and apply it to the formula we will get the following:

(187) Maximum Heart Rate=208−(0.7×30)

Zone 1 - Easy Going (50-60% of Max HR)

50-60% of 187 bpm = 93.5 to 112.2 bpm

Zone 2 - Steady and Comfortable (60-70% of Max HR)

60-70% of 187 bpm = 112.2 to 130.9 bpm

Zone 3 - Pushing It (70-80% of Max HR)

70-80% of 187 bpm = 130.9 to 149.6 bpm

Zone 4 - Challenging Yourself (80-90% of Max HR)

80-90% of 187 bpm = 149.6 to 168.3 bpm

Zone 5 - All Out (90-100% of Max HR)

90-100% of 187 bpm = 168.3 to 187 bpm

When someone talks about Zone 2 training we are referring to:

Zone 2 - Steady and Comfortable (60-70% of Max HR)

60-70% of 187 bpm = 112.2 to 130.9 bpm

Regardless of your fitness level, this intensity should feel very very easy compared to your typical high intensity interval training that historically receives a lot more glamour and fame in the fitness industry.

This seems simple enough and many places do a phenomenal job of explaining this concept in detail (see Finn Fielding’s write up for WHOOP in July 2023). But from a coaching perspective this is just not ideal for someone just getting started, and requires a little more nuance. 

Depending on your perspective you might be happy to hear that there is no such thing as going too easy on your easy days, and we’ll explain more about why you may actually want to use Zone 1 and not Zone 2.

Clearly using the Zone model for training is relatively simple when you have a max heart rate formula that can apply to most anyone and a range of numbers to follow based on your max heart rate. Important to remember though is that your max heart rate can change depending on your training state (if you have been following along, you know we’ve talked a bit about this in our Detraining article) with higher personal maximal heart rates in the detrained state and lower personal maximal heart rates in the trained state.

The three most important factors to therefore considering your heart rate zones:

1. Maximum Heart Rate - Having a good sense of what your maximum heart rate is will be important if you want to base your training off of your maximum heart rate. We encourage you to get tested at a laboratory in an exercise testing center when possible, but will go over other economical ways to do this in our next article on maximum heart rate so that you can be better prepared if the Tanaka equation is not what you find to be ideal for you
   
   
2. Training State - If you’re coming back from time off after a hard season or have not been training with an easy runs easy mindset for at least 6-months and possibly longer. For someone less trained we would actually recommend doing easy run training in Zone 1 to start and primarily at the lower end of Zone 2, and that’s because blood lactate is an important consideration often overlooked
   ‍
3. Weather - If it's really hot out you could have your heart rate naturally higher even at easy paces; this isn't because you did anything wrong, but just because your muscles and skin are competing for blood flow to cool your body off. We'll go into more detail about why this is in a future article, but for now just know that heart rate zones can get really wonky once you start getting overheated, and the weather is the largest factor of this

What Is Blood Lactate?

Imagine your muscles are like engines. When you run, these engines work hard and need fuel to keep going. The main fuel for your muscles is something called 'glucose', which comes from the food you eat.

Now, when your muscles use glucose in a normal, easy-going way (like when you're jogging slowly), they get plenty of oxygen, and this process creates energy and a bit of a waste product called carbon dioxide, which you breathe out.

But when you start running really hard (like in a sprint or a tough part of your run), your muscles need more energy quickly. There's not enough oxygen available to make this energy in the usual way. So, your muscles start a different process to make energy quickly. This process doesn't need oxygen and makes energy from glucose, but it also creates a byproduct called 'lactate' (or 'lactic acid').

At lower levels of effort, your body can clear this lactate away, using it as additional energy or getting rid of it. But when you're running really hard, lactate is produced faster than your body can remove it. This build-up of lactate in your blood is what's called 'blood lactate'.

Here's the thing: when lactate builds up, it can make your muscles feel tired and achy – it's part of the reason your legs might feel like jelly after a hard sprint or a long, intense run. That's your body telling you, "Hey, this is too much, I can't keep up!"

When it comes to training, understanding your lactate levels can help you train better, and not just when we are talking about the obvious burning sensation in our legs, but when considering Zone 1 vs. Zone 2.

Pulling from that same article created by WHOOP, we have the following figure:

On the y-axis you can see that 2mmol and 4 mmol have been predominantly highlighted relative to the zones for training. Physiologically, you are getting the most benefits for training adaptations when you are below 2mmol of lactate. Without getting lost in the weeds, different training states, nutrition, genetics, and training styles all impact when that lactate level of 2mmol is hit. You also are unlikely to ever feel a burning sensation when crossing over that specific lactate level.

The average untrained individual is often already close to that threshold just when going for a brisk walk. You may also find that 2mmol of lactate is achieved in moderately trained individuals when at the upper bounds of Zone 1 instead of Zone 2. 

Additionally, training below your 2mmol level can actually push the training intensity that will elicit 2mmol lactate up into Zone 3 over time as you become a more highly trained individual. Zone 3 is a zone that is often otherwise referred to as the gray zone (i.e. training zone that builds more fatigue without ample benefits).

What You Should Do

All of this is not to say that encouraging people to train in Zone 2 is bad or that Zone 2 is going to do damage, this is just to say that the goal of Zone 2 is more nuanced than just being Zone 2 and that the average running influencer who encourages you to go out and run at Zone 2 likely has no idea if Zone 2 is the right training intensity for your goals and training level, especially if maximizing your health benefits from your training is something you are aspiring to for the long-term. If you're just starting out this might mean going for longer brisk walks instead of longer easy runs. But remember, training is a holistic process and easy days are only part of the equation. If you have more questions or want to learn more about how we take your personal physiology into consideration, reach us at runbyryan@gmail.com.