In The Zone | Analysis of Heart Rate Training
Zone 2 is all the chat at the minute.
You’ve probably seen it littered all over Strava and social media captions; but what does it actually mean for YOU and your training?
‘Zone 2’ refers to a specific heart rate zone - with the most widely accepted definition being between 60-70% of your maximum heart rate (HR). It is used to describe training with minimal exertion (or RPE), which allows for quicker recovery and thus makes progressively increasing your weekly mileage easier without spiking risk of injury.
So for myself, roughly, this lies between 118bpm-136bpm as someone with a max HR of 195bpm.
When it comes to endurance training, learning how to pace yourself both in training and in an event can make or break success. Push too hard, too soon, and you’ll burn out; stay too easy, and you may never progress.
Using HR Zones in training can be hugely beneficial - and can have an awesome effect on your running, particularly when it comes to load management (i.e. strategic planning of one’s physical exertion over time). As an Ultrarunner, I personally use HR Zones for the majority of my sessions for exactly this reason - and have found it incredibly successful in allowing for high mileage weeks in the absence of injury.
But equally as a Coach, I have seen many situations where someone focusing on Heart Rate can be completely null and void. Therefore, I will caveat this with one key word: CONTEXT.
Hopefully by reading this, you will ascertain whether you should grab yourself a chest strap and jump on the HR Wagon; or whether your efforts are best placed elsewhere…
Why Use Heart Rate as a Performance Metric?
Heart Rate is essentially a live feedback loop between your heart and the demands placed on your body. Unlike pace, which can be skewed by terrain, weather, fatigue, or surface, HR reflects the internal load—how hard your body is actually working.
One of the handiest measures in this space is Resting Heart Rate (RHR) which, when tracked over time is a simple but powerful way of assessing:
General health: A consistently lower RHR is often linked with better cardiovascular (CV) health. Conversely, a sudden spike can flag excessive fatigue/overtraining, illness, or stress
Fitness improvements: As you build aerobic capacity (how well your body can take in, transport, and use oxygen to fuel prolonged exercise; the body’s ‘fuel tank’), the heart becomes more efficient—able to pump more blood per beat. This efficiency results in a lower RHR and faster recovery post-exercise.
Readiness to train: An unusually high RHR on waking can be a red flag that you’re not fully recovered and should take things back a notch or two.
Because HR accounts for both physical and emotional stressors, it’s probably the most holistic metric that goes beyond just running splits. Therefore, in the case of measuring RESTING heart rate, I would say this could apply to everyone looking to keep an eye on both their general health and improvements in their running.
BUT, as with any physiological metric, it is important not to get too bogged down in the numbers; use it as a guideline to make adjustments to your lifestyle and training, rather than a sole dictator of success/failure of a training week.
What is Zonal Training/Zone 2?
From determining your Maximum Heart Rate (MHR) using one of two ways - either a figure given by your smartwatch, OR the Karvonen Equation (MHR = 220 - Age) - you can then start to manage training loads through Zonal Training (bear in mind that the Karvonen Equation is a very rough idea, and can vary by up to +/- 20bpm depending on the individual).
Zonal training breaks down training intensity into specific “zones,” each corresponding to a percentage of your MHR. The typical 5-zone model looks like this:
Zone 1: Very light, recovery (<60% HR max)
Zone 2: Light aerobic (60–70% HR max)
Zone 3: Moderate, steady effort (70–80% HR max)
Zone 4: Threshold, hard (80–90% HR max)
Zone 5: Maximal, VO₂ max (90–100% HR max)
The idea behind this, as outlined in the introduction, is rooted in load management - ensuring that you aren’t overcooking the Rig in your training, while simultaneously ensuring that any effort sessions (ie speed work, intervals, tempo runs etc) are completed at an appropriate intensity.
General consensus for those that use this model is that Zone 3, or the ‘Nether Zone’ (for those who get the reference, we can be friends x), should be avoided if possible; meaning that easy sessions stay easy as determined by your body, and hard sessions are executed to a degree of difficulty that actually stimulates adaptation.
Put simply, ‘Run your hard runs hard, and your easy runs easy’ - using the objective data produced by heart rate monitor to quantify this effort, and thus guide you in pacing training runs.
Why Use Zonal Training?
I have found lots of success using HR Zones in my own training - and indeed many of my Athletes of TGPT will attest to its positive impact on their running.
It quantifies effort in a manner that adjusts according to your levels of fatigue - meaning that you can find the sweet spot for you in terms of frequency (number of times you run per week) and volume (how far you run over the course of a week).
Furthermore, it can contextualise exactly what an ‘easy run’ looks like for you in terms of pace - which I can almost guarantee is a hell of a lot slower than you think!
If you are a keen runner that has found progress stalling to a halt, I can bet a good price that it’ll be because you are running too hard too often - so utilising these training zones can rewrite the script and get you back on the wagon moving in the right direction.
For those on the opposite end of the spectrum, it can be a powerful motivator in pushing yourself on harder sessions - potentially more so than if you were doing it by feel (more on this below).
But is utilising HR in your training for everyone?
Why Are HR & Zonal Training NOT Appropriate?
While HR training sounds like the perfect science, it can be misleading for beginners and more regular runners alike for a variety of reasons:
Cardiac drift: HR naturally drifts upwards in warm conditions, or on long runs, even if pace is unchanged. If you are sticking strictly to Zonal training, you may misinterpret this as overexertion - when other factors are largely causing the rise.
Noise in the data: Wrist-based monitors can be inaccurate. Even chest straps need consistent use and calibration - so therefore, it is important to understand how different levels of effort FEEL, and subsequently draw upon both watch data AND your brain to determine how fast you should be running.
High variability: Beginners may find their HR shoots up quickly, even at a jog. This makes “staying in Zone 2” frustrating and demoralising. Learning how to control your HR is an artform that takes a hell of a long time to master - so it’s important to recognise that, particularly if you are starting your journey into running, HR control will almost certainly be up the spout. Using more subjective methods of managing effort, such as the Talk Test will be more applicable in keeping a lid on intensity
Running is inherently hard - especially in the first 6-12 months. There may be no such thing “easy running” when starting out, because even a pootle will feel exhausting as your body gets woken up to the shock/impact forces that it’s not used to.
If you spend your time stressing about ‘staying in Zone 2’, then I can promise you’ll find yourself up shit creek before you know it. You’ll be much better off focusing on the BASICS - consistency, frequency, progressively building volume, and basic strength — rather than obsessing over zones.
How to Get A Grip of HR & Zonal Training
Mastering the Art of HR Control takes time, discipline and consistency - as with any endeavour in the endurance space.
It took me a good 12-18 months to get it properly dialled in - so the first thing to mention is, it takes TIME.
There are a few things that you can do to help further your progress in controlling your HR, and thus maximising its impact on your running:
Nasal Breathing - the number 1 way to Get a Grip of HR lies in breathing patterns. One of my colleagues describes it perfectly as a ‘3 Gear System’. Gear 1 is entirely nasal - meaning both the inhale and exhale goes through your nose; Gear 2 being nasal in, oral out - and Gear 3 being fully oral.
Using your nose more when breathing during running activates the parasympathetic nervous system - often referred to as “rest and digest”. This calms the body and helps keep heart rate lower compared to shallow, rapid mouth breathing that triggers the sympathetic (“fight or flight”) response - which I am sure most runners (myself included) have experienced along the way.
This serves to keep you calmer, more efficient, and better oxygenated when logging ‘easy miles’ - it takes a hell of a lot of time to get the hang of, but honestly I would say this has had the most transformational effect on my endurance in the last 2 years. Not only does it help with reducing the physiological impact of a run on your body’s systems, but simultaneously helps with reaching the Promised Land of Autopilot during races.
The other main thing to consider when trying to improve your HR and Zone 2 training is recovery and stress management. Everything from sleep, nutrition and hydration, to psychological factors such as work, family and general life stressors.
Your heart responds to changes in the body’s condition - for example, if you’ve been on a bender the night before, and head out for a hungover plod, your working heart rate will be much higher. Same story if you try running soon after a monster roast on a Sunday.
Dialling in to all of your lifestyle factors will improve your ability to control your HR during exercise, which is one of the many reasons why you should take a comprehensive approach to maximising your performance.
I’m not saying you need to make running your entire personality. Just be mindful of the fact that looking after yourself slightly better will make HR control a million times more doable!
The Final Word
Heart rate training is a fantastic tool when used with purpose and context. It offers an internal measure of effort that pace alone can’t give you, particularly useful for endurance athletes training across varied terrains and long distances.
BUT it’s not the silver bullet that many sh*thouse influencers will have you believe—and it’s certainly not the only way to train.
For experienced athletes, zones help structure training and optimise adaptation - but equally, an understanding of subjective measures of effort (ie running to feel) is an essential tool to have in the armoury when HR data is skewed or unavailable. They should be used in tandem with one another to optimise results.
For newer runners, building the habit of consistent, sustainable training is ALWAYS more important than worrying about HR numbers. You are wasting your time if you keep your eyes glued to your watch, frustrated as to why it is telling you you are in cardiac arrest despite plodding at what feels like an easy pace.
In the end, think of heart rate as one of many tools in the box. Use it wisely, but don’t let it replace listening to the most important feedback system you already have: your own body. And not just for those towards the more experienced end of the spectrum…
