How to Use Zone Training to Your Running Advantage

Want to learn about how to use training zones in your running? Read the full article to learn more!

Zone training – such as the popular zone 2 running – is all the rage right now. If heart rate (HR) intensity zones feel overwhelming for you, you are not alone. This article answers the question of what is zone training, with the goal of providing a science-backed yet practical framework for quantifying your running intensity. 

Understanding training zones

Physiology exists on a spectrum, not in tidy zones. Training zones help quantify training and define workout intensity. 

You may notice that heart rate zones are defined differently based on where you read them. Many articles and training systems use a five-zone model. However, various five-zone models define zones 3, 4, and 5 differently. Most scientific literature uses either three-zone models, which will be the focus of this article. 

The three-zone model offers clear definitions of each training zone without overcomplicating training. It defines zone 1 as easy, zone 2 as moderate, and zone 3 as hard. 

For this framework, the important thresholds are the first ventilatory threshold (also called LT1), the second ventilatory threshold (also called LT2 or maximum lactate steady state), and VO2max. It can be a bit confusing, as the research literature calls LT1 “lactate threshold,” while coaching vernacular (as popularized by Dr. Jack Daniels) calls LT2 “lactate threshold.” For the sake of clarity, this article uses either LT1 or LT2, or the common vernacular of “aerobic threshold” and “lactate threshold.” 

 Zone 1 is easy, capped by LT1. Zone 2 is moderate, capped by LT2. High intensities such as VO2max are regulated to zone 3. When zones are divided into five, they are split up a bit differently. 

(For a breakdown of five zone training models, read this article by accomplished trail and ultra coach David Roche of SWAP Running.)

Main benefits of training within specific zones

Training zones provide us with a framework for prescribing training intensities. Running zones can guide the prescription of workouts and understanding how hard (or easy) certain runs should be. 

Training zones can provide structure for periodization and intensity distribution of your training. During different training phases, you may emphasize workouts in certain zones. For example, 5K specific training may include more zone 4 and zone 5 workouts. Marathon training may include workouts in zone 3.

The two most common training intensity distributions include: 

  • Polarized is 80-85% zone 1 (easy) and 15-20% zone 3 (hard), with very little zone 2 (moderate).
  • Pyramidal is 75-80% zone 1, 10-20% zone 2, and 5-10% zone 3. 

You may read misguided social media posts that overemphasize (or oversimplify) polarized training. Your training guides your intensity distribution following the principle of specificity. For example, a marathon runner may follow a polarized model in earlier training, followed by pyramidal model in the couple months before the race. Conversely, as demonstrated by a 2023 study in the Scandanavian Journal of Medicine and Science in Sports, a 5K runner would first do a pyramidal approach, and then a polarized approach closer to the race.

A closer look at training zones for runners

Let’s break down the three-zone model a little bit more. This model offers a clear-cut approach that can be applied to your training. Zone 1 is easy intensity, zone 2 is moderate, and zone 3 is hard.  

Zone 1 running (Easy Zone)

This is the bread and butter of endurance training. This is your easy running zone. Slower runs such as recovery runs and warm-ups and cooldowns are wrapped into this zone. If you are using a five-zone model, zone 1 and zone 2 occur here. 

 You are below LT1, so your breathing is comfortable – you can talk conversationally. You are oxidizing both fat and carbohydrates for energy production. Easy zone is sustainable for many hours, allowing you to accrue larger training volumes. A majority of your training should occur here. 

Zone 1 benefits include increases in mitochondrial density, muscle capillarization, and aerobic enzyme activity. If you spend enough training time in zone 2, you can improve your fatigue resistance (how long you can sustain running without decreasing your pace). 

Related: Are You Doing Your Easy Runs Right?

Zone 2 running (Moderate)

Once you cross the LT1/aerobic threshold, you enter zone 2. This zone is the “tempo” zone or moderate intensity zone. In terms of pacing, this is typically marathon pace to half marathon pace for many runners.  If you ever hear anyone discuss the “gray zone,” they are typically referring to zone 2. 

Moderate intensity is a range, not a singular pace. Threshold training will feel a bit harder than marathon pace. But in terms of physiological benefits and recovery rates, threshold pace, half marathon pace, and marathon pace all are classified as “moderate.”

This moderate zone is still aerobic running. The aerobic threshold indicates that a higher percentage of carbohydrates are now used for energy production. As a result, this pace is slightly more metabolically fatiguing – only sustainable for about 2.5 hours before fatigue occurs. 

Moderate zone training may get a bad reputation as the “gray zone.” Indeed, you do not want to run all of your training in this zone, due to the fatigue. However, when used appropriately, moderate intensity confers numerous benefits for long-distance runners. Training here improves aerobic threshold, running economy, and lactate threshold. Your body becomes better at storing and using glycogen, your fast-twitch muscle fibers become more oxidative, and you increase the size of slow-twitch muscle fibers. 

At the upper end of zone 2 is your second lactate threshold—or maximum lactate steady state. This is approximately your one-hour race effort. Glycolysis contributes even more to energy production at this point, but you have not yet reached the point where your physiology is unstable. Your lactate threshold runs fall into this category. 

Threshold training offers numerous benefits for distance runners. This intensity improves your ability to shuttle lactate back into the muscles for energy when running at moderately hard intensities. Cardiac output improves, as does the recruitment of intermediary muscle fibers. These workouts are intense enough to improve your lactate threshold and even velocity at VO2max, without excessive amount of fatigue. 

Related: Understanding Moderate Intensity Training on the Tread Lightly Podcast

Zone 3 running (Hard)

Zone 3 is most typically defined as the “VO2max” zone. Once you surpass your second lactate threshold, you are in the hard intensity training zone.  This zone encompasses interval training, including VO2max intervals, hill repeats, and critical speed intervals. (Supramaximal intensities are often lumped into this zone and are overall a very minor portion of endurance training.)

High intensity work offers value, even if you cannot significantly change your VO2max. This training intensity improves mitochondrial function, cardiac output, fast-twitch muscle fiber recruitment, and capillarization. You can improve your velocity at VO2max and your lactate threshold when training in this zone. If easy running builds a bigger foundation, hard running raises your ceiling. 

Related: How to Do Interval Workouts

How to determine your training zones

Typically, people associate training zones with heart rate training. Heart rate is certainly one metric that can be used for prescribing training zones. However, it is not the only metric. You can prescribe zones based on the talk test (breathing rate), paces, blood lactate levels, and rate of perceived exertion (RPE).

If you are using heart rate, you will want to perform a field test for accurate heart rate zones. The metabolic threshold of lactate threshold and heart rate for lactate threshold are closely correlated. A lactate threshold HR test will provide you with the heart rate associated with LT2 – which can provide a cut-off for zone 2 to zone 3. From there, you can figure out zone 1 (<85-88% of LTHR). You can learn how to perform a lactate threshold HR test here. You should repeat this test two or three times per year to adjust for training adaptations. 

These zone definitions come from a 2022 study in the International Journal of Sports Physiology and Performance and a 2022 review in Sports Medicine Open. You may see HR intensity zones outlined differently in other models more removed from the recent research.

As defined across various research studies, easy/zone 1 is:

  • 60-82% of heart rate max
  • RPE 4/10 or lower
  • Speech is conversational
  • Blood lactate <2.0 mmol/L

Moderate intensity/zone 2 is:

  • 83-87% of heart rate max
  • RPE 5-6/10 
  • Speaking in short phrases is possible 
  • Blood lactate 2.0-4.0 mmol/L

Hard intensity/Zone 3 is:

  • 88-99% of heart rate max
  • RPE 7/10 or higher
  • Speaking is difficult; may only be able to speak a word or two
  • Blood lactate 4.0-8.0 mmol/L (or even greater)

How to tailor your training zones to specific race distances and goals

On a recent episode of the Critical Oxygen podcast, sport scientist and endurance coach Jonah Rosner stated that the early preparation phase of training should be structured based on physiology, while race-specific training around the pace demands of the event. 

This approach, rooted in coaches such as Renato Canova, is what I take with my athletes. While I do think about all training zones in early phases of preparation (“non-linear periodization), I primarily consider the specific demands of the goal event in the 4-10 weeks prior to the event. This approach is called “funnel periodization.” 

Training Zones for Early Preparation 

The early preparation phase is between base-building and race-specific training. During this time, the focus is on improving all aspects of running fitness so that no particular weakness holds an athlete back in race-specific training. This phase involves a combination of interval runs, threshold workouts, and steady-state runs. 

Often, the workout focus will vary each week. Not many recreational athletes can tolerate two hard workouts per week, especially early in a training block. So, a training plan may include VO2max intervals one week, and a threshold workout the next week. 

Training Zones for 5K/10K Training

5K and 10K race paces are in zone 3 (hard intensity zone). If you are racing these events, you want to be adapted to both the metabolic and biomechanical demands of these intensities. To do so, you will focus on zone 3 workouts in your race-specific training. Advanced athletes may include tempo runs as a secondary workout, but those workouts have less time at intensity than in (half) marathon training.

 Interval workouts may include vVO2max intervals and slightly slower race pace intervals. If you are preparing for a 5K, that includes workouts with 15-25 minutes worth of work at 5K pace. For 10K training, you may include workouts with 20-35 minutes of time at 10K pace. 

Training Zones for Half Marathon/Marathon Training

Half marathon and marathon race paces are in zone 2 (moderate intensity zone). During marathon and half marathon specific training, training is likely pydramidal. 70-80% of training volume is easy, and most workouts occurring in the moderate intensity range. Very little training is done in the hard training zone, especially on a weekly basis. Workouts in the hard training zone are typically closer to 8K-10K pace instead of vVO2max. 

Workouts include marathon or half marathon tempo runs (race pace tempos), threshold intervals, and progression runs. These workouts will typically include 30-60 minutes of accumulated work duration (sometimes longer at marathon pace). 

Feeling overwhelmed? A running coach can help

Hopefully, defining training zones within a three-zone model streamlines the concept. Zone training for running can be helpful, but only so much as it does not overly complicate your training. While elite systems may have more nuance (such as six-zone models), most recreational runners will benefit from thinking about their training as easy, moderate, and hard. A running coach can help you implement different training zones while preparing properly for your goal races.

Want more training advice, such as on training zones? Follow Laura Norris Running on Instagram for science-backed training information, study breakdowns, workouts, and more. 

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