Introducing Zone Training
As a high school runner, before I knew anything about zone training, my coach would provide me training programs every month. A departure from the tools that we utilize today, these programs were always crafted on pen and paper. Words like “Easy” or “Steady” were used to indicate intensity. Though I had an implicit understanding of what this entailed back then, by today’s standards this language may be seen as vague or ambiguous.
Being a runner in 2024 comes with the opportunity to utilize a variety of tools, built to aid in training and race-day performance. After each run, my Garmin feels compelled to tell me how I’m progressing in my training. Other gadgets on the market, like Whoop’s wristbands and Stryd’s running power meters, add even more layers of information. Gone are the days of pen-and-paper training plans. Today, quantitative data has won the hearts and minds of runners across the globe.
The heart rate zones framework has been a popular reference point for those who are choosing to organize training load according to one particular piece of data – heart rate, collected from either the wrist, upper arm or chest. Heart rate can be correlated with intensity during endurance training. Considering this, coaches and athletes can plan training sessions to fall within a certain intensity range. The desired intensity depends on the goal race, workout purpose and stage in a training cycle. Understanding how to apply these zones is crucial for progressing toward a big race or adventure while managing rest and recovery.
This article is for those who want to make sense and use of heart rate zones. We’ll start by defining heart rate zone training and some it’s nuances. Then we’ll move onto discussing how to apply the framework during your next training block.
What Are Heart Rate Zones?
Heart rate zone training comes from the understanding that the body controls for energy production according to its rate of work. For example, the mix of energy systems used in a 1-mile race differ significantly from those used in a marathon. Heart rate zone training is utilized with the intention of building volume (or time) spent running at race specific intensities. This protocol consists of dividing ranges of exercise intensity into segments that are each associated with a heart rate range. The intensity range goes from walking to maximum sustained exertion running.
The number of zones and how they’re structured will often vary depending on the creator. For simplicity, I’ll reference a 5-zone framework in this article (below). However, other zone frameworks consist of 4 or even 3 zones in association with intensity-related metabolic changes.
| Zone | Name | Intensity | Use |
| 1 | Active Recovery | Very Light | Hiking, active recovery |
| 2 | Easy | Light | Easy days, medium/long runs |
| 3 | Aerobic | Moderate | Tempo work |
| 4 | Threshold | Hard | Strength-based intervals |
| 5 | VO2 Max | Maximum | Power-based intervals |
The Wandering Heart and You
Here’s the deal with your heart rate while running: it’s not always a perfect indicator of effort. During long efforts, for example, heart rate can slowly increase over time. This is known as cardiac drift, occurring in response to an increase in the body’s core temperature and sweat losses. As such, running in hot environments can create a bigger discrepancy between heart rate and perceived effort.
Additionally, heart rate numbers during submaximal exercise can be swayed by our emotions – a charged atmosphere can lead to higher average heart rate values due to an increase in sympathetic nervous system tone.
Experience level also plays a role. Seasoned runners are able to pump more blood per beat to the working muscle. This allows them to maintain lower heart rates at higher efforts. In contrast, those who are new to the sport may see higher heart rate values relative to the same level of perceived effort.
Given these variables, it’s clear that heart rate numbers should be taken with a grain of caution. But if heart rate can sometimes mislead, how do we make sense of our training? Connecting intensity zones with target race paces can help to create a more complete picture.
The “Golden” Zone 2
Zone 2 training is often hailed as the “golden” zone for distance runners. For the past few years, influential coaches, physiologists and runners alike have been taking to social media and speaking to the sweet, sweet taste of this secret sauce. The perfect amount of Zone 2 running (approximately 60 – 70% of maximum heart rate) to add to any training recipe, they say, is 80% of total volume. Regardless of how much time it contributes toward your weekly volume, running within the lower zones of 1 and 2 allows you to build a strong aerobic engine without risking mechanical failure.
What does Zone 2 feel like?
As they say, keep it conversational. Learn how to breathe deep and sink into an easy rhythm. To ensure that you’re not feeling any pressure to maintain a set pace, run to duration on these days. Runners I coach slowly progress up to an hour of running at this intensity before I introduce any harder running. The less experience you have, the more time you’ll need to spend running within this zone each week.
Which Zone and When?
After building a foundation of easy Zone 1 and 2 running, you can start to build volume around harder efforts. The next zone up will typically be the main intensity range that you live in during a marathon. Workouts in Zone 3 might include tempo runs or long intervals at marathon pace, equivalent to a steady, harder than easy but controlled, effort. Start by running for 20 minutes at your target marathon pace, before progressing this workout by adding time, or by slowly increasing your speed towards the end. If you’re really struggling for air at the end of these workouts, adjust your goal times accordingly. Alongside Zone 2 days, one of these sessions per week is plenty.
Once you feel that your body is starting to recover well from Zone 3 work, you can add a little spice with Zone 4 training. Aim to spend more time here if you’re looking to perfect the 5 and 10 kilometer distances.
Zone 4 interval training allows you to safely build volume at this intensity. Considering that you’re likely working within the Zone 4 heart rate range during 5 kilometer and 10 kilometer races, any interval training may be modeled off these target paces. Start with 2 to 3 minute intervals at your target 10 kilometer race pace, before introducing shorter intervals – 300 to 400 meters – at 5 kilometer race pace. Focus on starting small, before slowly increasing the number of intervals while maintaining a consistent pace. Try to keep the recovery to no more than the equivalent of the interval duration. If you find that you need more recovery time to keep a consistent pace, take your foot off the gas and slow down your target times. Treat Zone 4 work as the crescendo of your training block.
During your final weeks of preparation toward a key race, your week will likely include one Zone 3 day, Zone 4 interval day, as well as one day dedicated to running long in Zone 2.
Final Note on Zone Training
When thinking about the zones framework, context is everything. Three things to consider when organizing your next training block are your:
1) Level of experience
2) Current state of fitness
3) Target race, goal or adventure
Within the design of any program, your progression in training should always be cyclical. At each stage in the cycle of your training block, a different zone will become the focal point. The amount of volume that you work up to within each zone will depend on the intensity range that you’ll be utilizing the most while trying to hit your next running goal. In that sense, heart rate zone training should never exist in a vacuum. Instead, consider the zones as a collection of tools – at any given time, the one that you use will depend on the project at hand.
References
Power, S. K., Howley, E. T., & Quindry, J. (2008). Exercise Physiology: Theory and Application to Fitness and Performance. McGraw Hill: New York, NY.
Ryan Woolley is a coach with Team RunRun based in New Zealand. As a coach, he focuses on strength for performance and injury prevention. He uses his 20 years of competitive experience across many distances and terrains to guide his athletes towards their goals. Ryan also has a strong technical understanding of exercise physiology (BSc, MA) and applies it to his coaching.