Triathlon bike training: What is a training zone?

You’ll hear a lot of triathletes talking about their heart rate zones and power zones. Heck, chances are you’ve heard me talking at length about “zone 2 training.” At a base level, zone training allows you to train at specific intensities to develop fitness over time. When it comes to cycling most people will focus on their functional threshold power, or FTP for short. 

Here’s what you’ll learn in this article: 

• The different training zones from one to five (and beyond);

• The effort level of each zone;

• How to use each zone and when to use it; and

• How to set the correct training zones for you so that you can maximize your training to build fitness the right way.

Triathlon Cycling Training Power “Zones” Explained

In our MOTTIV training app, we use five different zones (and a bonus “max effort” intensity). 

This is what a Zones chart looks like for one athlete, but just remember YOUR numbers will look different than these ones.  (So don't use this athlete's chart for your Zones.)
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Zone 1: Recovery

This zone is great for total recovery between hard intervals, during a recovery day, a long endurance building ride, or while warming up. The effort should be a little harder than a nonchalant spin on the bike, but it should not feel challenging at all. This zone burns fat and builds endurance.

Training in this zone is best done by rate of perceived exertion (RPE) or heart rate. This training RPE of 1-2 out of 10, and an HR of less than 60% of your maximum heart rate. 

Throughout your annual training cycle, you should spend 40-50% of your time in Zone 1. 

Zone 2: Cardio

This is the most important zone to spend time training in! The intensity is low enough where you can carry on a conversation without gasping for breath. Zone 2 builds endurance and burns more fat during the workout; if you get adapted to burning fat as fuel you’ll have a nearly endless supply of energy.

Training in this zone is best done by rate of perceived exertion or heart rate. This training RPE of 3-4 out of 10, and an HR of 60-77% of your maximum heart rate.

Throughout your annual training cycle, you should spend 30-50% of your time training in Zone 2.

Zone 3: Tempo

This zone is somewhat of a no-man’s land. The intensity is somewhat hard, but sustainable for long workouts, it’s often where a lot of race pacing lies. The trouble is, however, it’s hard enough to cause a lot of stress on your body which is difficult to recover from but it’s not hard enough to make you much faster. You can spend a lot of time in this zone, so it’s very stressful on the body.

This zone is best saved for race pace intervals to prepare you for a race, and race day.

Training in this training zone should be done off rate of perceived exertion, heart rate, or power. Often it’s best to use a combination of all three so that on race day you can “feel” what an appropriate race effort is while having some metrics to help determine if what you’re feeling is true.

Throughout your annual training cycle, you should spend 5-10% of your time training in Zone 3.

Zone 4: VO2 Max

This zone features a level of intensity that’s very hard. You’ll be able to sustain this for somewhere between six and 30 minutes depending on your fitness level. Training in Zone 4 does allow you to build the amount of oxygen you can use for hard exercise.

Your cycling FTP will lie within this zone.

At the higher intensities we recommend using power, as opposed to heart rate, because heart rate often takes a long time to climb so you aren’t getting an accurate reading of your effort level at the higher intensities.

Training in this zone is best done by rate of perceived exertion or power. This training RPE of 7-8 out of 10, and a power of 91-105% of FTP.

Throughout your annual training cycle, you should spend 5-10% of your time training in Zone 4. 

Zone 5: Speed and Power

This zone works your top end speed and power. It’s incredibly hard, but sustainable for three to four minutes. Training in this zone builds your maximal muscular speed, power, and strength. 

Training in this zone is best done by rate of perceived exertion or power. This training RPE of 8-9 out of 10, and a power of greater than 105% of FTP.

Throughout your annual training cycle, you should spend 5-10% of your time training in Zone 5.

Max Effort/Neuro-Muscular Power

When “max effort” is on the training schedule that means the hardest effort you can produce for the entirety of the prescribed time period. 

You will go as hard as you possibly can without fading by the end of the interval or in the final interval you do, end feeling like you could have squeaked out one more interval.. For example, a 15 second max effort would be more power than max effort over 60 seconds.

How to use triathlon training zones for cycling

In terms of structuring your training, there are two components that will have the largest impact on your overall fitness: volume and intensity. Volume is the amount of swim, bike, and run training you do. Intensity is how hard you do them.

Low intensity training increases your total amount of available energy by increasing mitochondria, while the high-intensity training makes the mitochondria fire better. The best and safest way to build training volume is to do so at an easy effort. Roughly 75-80% of your total annual training time should be easy, low-intensity training in zones one and two. 

Long distance training at an easy effort build’s your heart’s capacity to pump more oxygen-rich blood to your working muscles, decreases your injury risk,is less fatigue inducing, keeps your stress hormones low, and builds your aerobic engine. 

The key to getting the training balance correct is to develop a bigger base of low intensity training during the off-season and prior to starting a race-specific training plan, performing low-intensity sessions to acclimate your body to the long endurance day of a triathlon. 

What this might look like for you is building your base of fitness during the off-season with a significant amount of low-intensity training, something like 90-100% of the time. Then, come race season, you can ratchet up the amount of intensity at higher powers and heart rates to build more fitness and increase your capacity for harder, sustained efforts required on race day.

Closer to races you’ll want to spend more and more time in Zone 3 and low Zone 4 to refine your race pacing ability.

How to put this into practice

Using a heart rate strap for low intensity workouts will provide you with real-time insights into your intensity. If your heart starts beating too rapidly, you can dial it back a notch or two. The heart rate strap is a great tool for beginners and experienced triathletes looking for instant feedback on their training and progress.

Heart rate does have its limitations, especially for high intensity training. As I mentioned above, heart rate often takes a long time to climb so you aren’t getting an accurate reading of your effort level at the higher intensities. When training at high intensity, think VO2Max (Zone 4), and speed and power (Zone 5) sessions, you’ll want to utilize a power meter on the bike for the most effective way to build bike fitness.

Different types of training methods

Polarized vs Pyramidial vs. Maffetone Method vs Zone 2 Training

Polarized training focuses on spending 75-80% of your training time in zones one and two. This does build your aerobic base and help develop key performance indicators like your heart and lungs. 

Then, you devote 20-25% of training time to strictly high intensity workouts in zones four and five (there is zero time spent in zone three) which, over time, will help you develop that “all-out” energy for a potential sprint finish at your next triathlon.

This is great in theory, however putting this into practice is quite hard. Spending 20% of training time in zones four and five is a lot of training at a very high intensity, it tends to beat down the body quite a bit. It’s also fairly difficult for athletes to completely skip the zone three intensity entirely and get straight up to zones four and five. Finally, this method doesn’t allow the athlete to refine their moderate intensity race pacing effort..

What I recommend and the reason we use a pyramidal approach in the MOTTIV training app, rather than a strictly polarized model where the training is either low intensity or extremely high intensity, is that it allows you to get comfortable at race pace without spending too much time there which can be detrimental to your health. 

This pyramidial method incorporates recovery throughout the week between sessions. It also allows you to hit the hard workouts with confidence.

That 80% of low-intensity work will be in Zones 1 and 2. Now, when you’re training in Zones 1 and 2 I recommend you go by heart rate rather than power. The reason for this is that your heart rate will adjust to the weather conditions or how you’re personally feeling on any given day. Sometimes you simply won’t be able to maintain a power level at your Zone 1 or 2 heart rate and that’s totally fine. 

Your body doesn’t know power or pace. It does, however, know heart rate and when you train too hard that’s when you end up not being able to make progress. Again, in Zones 1 and 2 focusing on getting your heart rate correct. In my Triathlon Bike Foundations book, I explain my system to help any triathlete get better at the bike. It includes how to properly use power and pacing to achieve your best result and how to maximize your training time by eliminating needless hours in the saddle.

The Maffetone Method, or “MAF Method,” and Zone 2 training is heart-rate training designed to keep you under your aerobic threshold. To accomplish this, you log your training miles under a certain heart rate which you calculate by subtracting your age from the number 180.

By training exclusively at a low heart rate, you’ll undoubtedly increase your endurance by logging more miles with less stress on your body. As you continue with this style of training you can increase your speed and power on the bike while staying at the same low heart rate.

The issue with these training methods is that most people who use them spend all their time at low intensity Zones 1 and 2. However, we don’t just need to build more mitochondria with low intensity training, we need to teach the mitochondria how to fire well with the high intensity training.  

People who exclusively do low intensity training often feel very good, but they don’t make progress for very long because they’re not doing any high intensity training.

How to determine the correct training zones for cycling

To start training with the correct zones, in this instance we’ll refer to power zones, the first thing you’ll need to do is a functional threshold power (FTP) test. This is the sustained power you’d theoretically be able to hold for 60 minutes.

What you’ll need:

• Power meter

• Indoor bike trainer if you plan to do the test inside

• Flat, long stretch of uninterrupted road if you plan to do the test outside

What you’ll do:

• Start with a 10 minute warm-up where at the end of that half-hour you’re going pretty close to race pace and your heart rate is elevated

• Ride lightly for 5 minutes so that you’re fully recovered before the test

• Settle in for 20 minutes of challenging fun!

The goal of this test is to hold the highest amount of power you possibly can for the 20 minutes. You’ll want to pace this test properly. Here’s how:

• Begin with the first five to seven minutes feeling strenuous but not too hard. You don’t want this to feel like an effort level that’s unsustainable for the entire 20 minutes

• Increase your pace and cadence so the effort level becomes a bit more taxing. Keep it in mind though, you still have more than 10 minutes remaining so the effort should still be sustainable

• After 15 to 17 minutes if it feels incredibly challenging but you’re still going, you’re hitting the pacing just right

• After 17 minutes, give it all you got and go for broke. Whatever you have left in the tank should be coming out through the pedals in the final minutes

Now, once you’ve stopped sobbing and have gathered yourself again, you can calculate your FTP. Find your average power of the 20 minute stretch. Next, take 95% of that number. That’s your FTP. For example, if you averaged 185 watts during the 20 minute test your FTP would be roughly 176 watts.

You’ll set your power zones as a percentage of your FTP. This will guide your training.

You can also use the Zwift Ramp test. This test isn’t as taxing on your body as the full 20 minute test I just described, which is why I like the Zwift Ramp test. The pain here lasts only four or five minutes, whereas the pain in a 20 minute test lasts 20 minutes. 

Recovery time after a ramp test is only a matter of hours because you haven’t totally depleted your muscle glycogen stores or built up a large amount of lactic acid. Recovering from a 20, or even a 60 minute FTP test, can take days.

Additionally, it’s a lot easier to pace and dig deep for four or five minutes as opposed to 20 minutes. Also, the ramp test gives you a solid maximum heart rate number unlike the 20 minute effort. So at the end of the ramp test you’ll be able to build your power and heart rate zones.

Most people will start out around 100 watts for a five minute warm-up period and then it ramps up each minute from there until you can’t go any longer. You’ll take 75% of your best one-minute power output as your FTP.

Putting your training zones for cycling into practice

To structure your training plan, begin as far out from your race season as possible. This is where you’ll spend most of your time in Zone 2 to build your aerobic base and in Zones 4 and 5 building up your strength and your speed.

If you’re three or four months away from your race, for example, you’ll start bringing up your long, steady efforts (Zone 2) and bringing down your high end speed and power efforts (Zones 4, 5, and beyond) so that the majority of your training closer to your event is at or at least near your ideal race pace.

If you’d like a totally done-for-you training plan that incorporates the proper structure of zone-based training so that you can maximize your fitness and finish feeling strong, check out our Beginner Guides to Sprint, Olympic, Half Ironman, and Ironman Training.

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