Using Training Zones
Training zones come in many forms, and their application and use can be a little confusing. This article aims to clarify what they are for, how they should be used, and when you might consider making your own judgment rather than just relying on the data.
When an athlete starts out on their endurance training journey, it’s usually best to keep things simple and work up from there. Having the experience to initially achieve, and also be able to ‘feel’ a range of exercise intensities is often beyond a beginner athlete. This could be for a number of reasons - perhaps they think that training should always be hard (in order to get better / faster), therefore struggle mentally with the easier intensities; likewise, they might not have learned how to really push themselves to the limit and as a result cannot get to the highest ends of the intensity scale.
Also when you are not technically proficient (efficient) and not that fit, sometimes it seems like you only ever really have one speed/intensity. Easier efforts just seem too slow, and you can’t sustain hard efforts for very long at all, so you always end up ‘in the middle’. For the triathlete, this can often mean that without guidance the vast majority of their training all ends up at the same intensity.
The reason why you want to avoid this ‘in the middle training’ is that different intensities bring different benefits - so to really get the most out of your training, you’ll need to not only train at different intensities but also identify which ones are most important for you to work on / improve, as well as the correct ‘mix’ of intensities to best suit your goals.
So unless you are just starting out, where perhaps just breaking it up into ‘easy’ or ‘hard’ is the best way forward, training zones can be a useful tool to help you identify a whole range of intensities outside of the middle or ‘grey’ zone, as it’s sometimes called.
There are many different methodologies or types of training zones out there to use, utilizing anywhere from three up to seven or eight (or more!) different zones. Whatever method you choose, there will be a need to test yourself and identify a physiological marker (for example, anaerobic threshold). This marker is then compared to the corresponding heart rate, pace, or power at the point at which it occurs, from which you can then determine your training zones (defined bands of either heart rate, pace, or power).
These zones will then give you a good idea of what kind of intensity to training at for a given duration. This enables you to better target the (goal-driven) ideal physiological adaptations you are looking for by training at the right intensity for a certain duration. If you are aiming to go out and do a long easy ride, to help with your aerobic efficiency, there is really no benefit from going way too hard than having to stop halfway. Not only have you not completed the duration goal, but you will likely have worked too hard to get an efficient adaptation of the intended system. Conversely, a series of short hard intervals won’t have as much effect if you don’t get up to the required intensity.
So in summary, training zones are a great guide for an athlete that wants to begin structured training but hasn’t really developed a feel for identifying different training intensities. But there are a couple of potential pitfalls, and once you are fairly experienced there can definitely be an advantage to allowing a more flexible approach.
Starting with the pitfalls - a common occurrence is that the metric becomes the goal. This is not so surprising, really, as it’s the focus for a lot of training sessions, and it’s natural to become invested in what we focus on. For example, you could care more about hitting power zone targets in interval sessions than really learning how to best use that power in a variety of race situations. Perhaps you have got your highest zone 4 power ever, but it begins to rain on a technical bike circuit with fast downhills. You’ve focused on output but your bike handling and confidence in the rain are really poor through lack of practice and you lose a lot of time on the descents. This is not to say the higher power wasn’t useful - just that perhaps a more balanced training approach could have given a better outcome.
Perhaps you have chased that training load line up and up (more is always better, surely?) by focusing on a lot of training sessions in the ‘tempo’ zone (which is great for getting high training load numbers!) But your key event is a long-distance triathlon, and while a high training load is important, you just don’t have that aerobic base to rely on. As a result, you take on a huge amount of carbs, and either bonk anyway (because you burn carbs really quickly) or have gastric issues.
The key to avoiding all this is to recognise that training zones (and metrics) are a tool to use in order to achieve your goals and, like any tool, can be used correctly at the right time or inappropriately.
Once you have used training zones for a long period of time, and have that information to reference against, you will begin to feel what an ‘endurance zone’ or ‘threshold’ feels like. At this point, you can start to be a little more flexible with how you use them in training. One thing you will realise is that some days, despite your watch/bike computer/pool clock telling you one thing, it feels like another. Sometimes sessions that should be easy enough feel tough, or perhaps you feel like you are flying with not a lot of effort on another day. This highlights the ‘assumptions’ that are made using training zones - and for most people, they will be correct for most days, but not always. These issues are:
Zones are based on identifying one point on a curve (typically)
Zones are based on a test on a day when you are fresh (however, some coaches will test fatigued, or even perhaps run testing off a hard bike for triathletes)
Zone percentages are defined from a ‘standard population’ of data
You are not a robot. Things change from day to day (sleep, mood, nutrition, stress levels, etc.)
So how do you know if you are really having one of these days, rather than perhaps just a little unmotivated and you should just get on with it? Well, there is no way of being 100% sure, but you can use your knowledge to decide. Have you been training a lot recently and are a bit fatigued? Could you be coming down with something? How well have you been recovering? Perhaps you’ve not tested recently, and your zones are out of alignment with your current fitness. Perhaps you are on a ‘float’ day and should just make the most of it? Are you in the middle of a race, well rested and pumped full of adrenaline so your heart rate is well over what it would normally be?
Once you have used the zones and built up an idea of how they feel, and how you typically respond to certain situations, you can make a call on whether to go with it or make your own decision. You can also compare more than one method of training zone - what does the power/pace data say vs the heart rate data? Never just rely on the numbers, use them as a decision-making tool along with all the other factors, and you’ll be much more likely to make the correct training and racing decisions.
Kevin opened a B&B for cyclists in France in 2014, & then a year later decided to start a cycle coaching (level 3) qualification. This was mainly in order to be able to better support his guests (but also to make his own training more effective too). At the B&B he runs the odd training camp for cyclists but mainly offers coaching advice while guiding guests. An engineer by background, he happy diving into all sorts of training data, but also understanding that coaching is about much more than just the numbers!
After being introduced to triathlon by a good friend & then taking part in races for a couple of years he decided that a level 2 coaching course with British Triathlon was the way forward, completing this in 2019.
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