Zone 2 is perhaps the most talked about cycling training zone…

Both the scientific literature and anecdotal evidence from both amateur and professional cyclists suggest that a polarised or pyramidal training models are very often the most optimal means of distributing training intensity to achieve long-term improvements.

With this understanding, Zone 2 is the intensity range you’ll likely be spending the vast majority of your training time in, so it’s a crucial part of your training program to get right.

Let’s try to better get to grips with what Zone 2 is and how it’s calculated, the exact performance benefits it offers and then look at some ideal workouts you can use.

What Is Zone 2?

Zone 2 most commonly refers to the 2nd zone in a 6-7 zone scale, often referred to as the Andy Coggan training zones.

It’s a lower intensity training zone that’s a step up from a pure “recovery” intensity (useful for active recovery rides and recovery intervals between high intensity efforts) and one below a “tempo” intensity in the 6-7 zone model:

Zone 2 is commonly associated with a period or phase of the training cycle that’s widely referred to as the “base training” period, and is perhaps THE intensity range of choice to strengthen the foundational aerobic fitness which will support higher intensity training further down the line.

That being said, it’s an intensity that’ll feature in nearly all phases/periods of the training cycle for the vast majority of cyclists, just with the proportion of time in this zone altering from phase to phase depending on the goal(s) of that particular phase.

⚠️ IMPORTANT:

Zone 2 isn’t to be confused with the 2nd of 3 “zones” in the polarised/pyramidal model:

In the 3-zone model, the 2nd “Zone” (or more accurately “domain”) isn’t usually referred to as “Zone 2”, but is the range which sits between two key anchor points used in this model, usually Lactate Threshold 1 and 2 (also known as LT1 and LT2).

These can also be marked by Ventilatory Threshold 1 (VT1) as the first anchor point and several non-lactate markers as the second (FTP, CP etc).

Within a 3-Zone model, Zone 2 from the 6-7 zone scale would fall within Zone 1, I.e. below the first anchor point (e.g. LT1, VT1 etc).

How Is Zone 2 Calculated?

Zone 2 can is most often calculated as a % of a threshold value, commonly Functional Threshold Power or FTP, as well as Threshold Heart Rate (THR), but can be applied to Maximum HR (MHR) and rating of perceived exertion (RPE) too.

To calculate your FTP or THR, you’ll need to perform the appropriate test protocols, which we discuss in both our Cycling Physiology Guide and on our Cycling Training Zones article.

Calculation:

Apply the following %s to whichever value you choose to use (power, HR or RPE):

55-75% FTP
68-85% THR
60-70% MHR
3-4 out of 10 RPE

As an example, let’s take an athlete with a 300W FTP, 172BPM THR and a 195BPM MHR:

55-75% of 300W FTP = 165-225W
68-85% of 172BPM THR = 117-146BPM
60-70% of 195BPM MHR = 117-137BPM

Note that there will generally be slight differences in exact intensity ranges based on whichever value is used.

The key takeaway is that Zone 2 is a range and sharp metabolic changes won’t occur from the lower end of the zone to the upper end.

This makes training in this particular zone is fairly straightforward given the wider wattage/HR range compared to training zones above the second threshold.

Next, let’s look at some of the reasons to train within this intensity range…

Zone 2 Training Benefits

How effective is training in the Zone 2 range?

There are several important physiological benefits to training at this intensity:

Mitochondrial Content
Training for sustained periods at a Zone 2 level helps to increase mitochondrial density within the Type I (slow twitch) muscle fibres. Mitochondria are frequently referred to as “the powerhouse of the cell” and these are the organelles which process oxygen to produce ATP, the body’s energy currency. The more mitochondria in the muscle cells, the better for endurance athletes like cyclists.
Capillary Density
Zone 2 builds capillary density around the Type I fibres. Capillaries are the blood vessels or “pipe work” that deliver oxygenated blood to the muscles (where this oxygen can then diffuse out of the blood and into the muscle cells) and remove metabolic byproducts from the muscles, including lactate and CO2. More capillaries tend to result in greater the delivery of oxygenated blood (a large part of achieving a higher VO2max) and greater clearance of substances linked with fatigue, but also enhanced movement of useful energy sources like lactate out of the exercising muscle cells and out to other tissue that can uptake it.
Greater Oxidative Enzyme Activity
Improvements in oxidative enzyme activity lead to faster processing of oxygen to produce energy, resulting in a greater energy turnover.
Cardiac Adaptations
Important cardiac adaptations are also stimulated by training in Zone 2 for sustained periods, including stroke volume (i.e. the amount of blood that is pumped by the left ventricle per beat), again demonstrating the effectiveness of Zone 2 training for enhancements in VO2max (an ability often only associated with high intensity training).
Higher “FatMax”
Through development of the Type I muscle fibres, Zone 2 training helps to improve endurance from a metabolic perspective by increasing the maximum power output at which you can still burn predominantly fat for fuel (this value is often called “FatMax”). This is incredibly important for endurance athletes, since fat is a far more abundant fuel source compared to carbohydrate.

*Zone 2 rides will feature prominently in most cyclist’s “base” or early-season preparation, since it’s great for establishing a firm aerobic foundation with which to then build on top of.*

Psychologically-speaking, what’s nice about Zone 2 training is that it’s relatively relaxing, low stress day-to-day (easy to recover quickly from) and can serve as a productive break from highly-structured, higher intensity training, the latter of which requires a great deal of mental focus and pain tolerance.

Common Questions

There are some questions and queries around how to practically perform Zone 2 training that pop up repeatedly, and here are the main ones:

”What’s the best way to stay in Zone 2?”

Due to variables like terrain, weather and also riding style, it can be difficult for some cyclists to accumulate the necessary time in the correct intensity range during a Zone 2-focused ride. To help with this, here are a few suggestions:

Try choosing training routes that are flat or have shallow rolling hills
Avoid high traffic areas which result in stop-start riding to the best of your ability
In hilly areas, consider easier gear ratios, so that intensity can be kept necessarily low on steeper gradients
Make the current power field on your head unit large and visible, so you can regularly check your intensity
Extend the duration of your rides if they feature long descents where pedalling isn’t possible so that the desired time can still be accumulated.

”How long should Zone 2 training be?”

Typical ride durations for Zone 2 training will be 2-5 hours for most cyclists.

To induce the desired adaptive stimulus sought from this form of training, rides will need to be somewhat long duration to cause some level of fatigue in the Type I fibres, and ideally deplete muscle glycogen stores to a reasonably low level.

That being said, a Zone 2 intensity can be used in shorter duration ‘maintenance’ rides, e.g. during a recovery week, where it may make sense to raise the intensity above a Zone 1 level (e.g. to prevent the legs from becoming too lethargic and to better move oxygen around the body) but still keep the overall training stress of such a ride low.

“How often should I ride in Zone 2?”

The quantity and frequency at which you might train in this intensity zone will depend on several factors, including the cycling discipline(s) you focus on, your fitness or racing goals, your training history, as well as your time availability.

Most cyclists will generally perform between 2-4 Zone 2 rides per week in that 2-5 hour duration range, given that a typical training week will also include 1-2 higher intensity sessions and either active recovery sessions or complete days off the bike.

”What’s the best cadence for Zone 2 training?”

Zone 2 training can be performed at whatever cadence is most natural and comfortable for you. There may be some benefit to slightly higher cadences during some Zone 2 training sessions given that there is some evidence linking sheer amount of muscle contractions to the relevant adaptive stimulus.

That being said, the scientific literature suggests that cyclists default to the cadence which is most efficient for them. Riding most efficiently should allow for the greatest amount of time to be accumulated in such a ride, so freely-chosen cadence should support these specific training goals well.

”Should I perform Zone 2 training in a fasted state?”

There is some evidence to suggest that periodising your nutrition in accordance with the training to be performed, especially in the context of restricting carbohydrates may help to stimulate stronger signals for adaptation specifically in terms of mitochondrial biogenesis. This may suggest that for some athletes, riding in a low carbohydrate state may provide marginal improvements to the response yielded from low intensity, Zone 2 training.

In our experience, the effectiveness of this tactic is highly individual, and some cyclists may find it difficult to fit into their schedule (e.g. if they ride later in the day after eating earlier on) or notice a reduced rate of recovery following sessions.

However, if an athlete is time-poor and is looking to maximise all potential gains in fitness from this part of their training program, fasting or training with low carbohydrate availability may serve this goal well.

We have few posts on this subject that may be worth checking out if you are interesting in this particular topic:

Is seated or standing pedalling best?

Zone 2 training can be performed using both seated and standing pedalling styles/techniques.

Due to the ideal choice of terrain, it’s likely the vast majority of such rides will be spent seated, but keeping intensity down to a sufficiently low level on steeper climbs can be more easily achieved by standing on the pedals, since most cyclists will find this easier than staying seated when cadence drops.

Zone 2 Workouts

Zone 2 training need not be complex or highly structured. Here are two simple but effective examples we use routinely with coached athletes:

Long-Duration Steady Ride (Outdoors)

These rides are typically 2-5 hours in duration, where intensity is kept within a Zone 2 range as much as is practically possible.

Flatter or shallow rolling terrain is best for these workouts, since a lack of steep uphill gradients helps avoid being pushed into higher training intensities and fewer steep descents will remove the need to coast or soft-pedal for too long.

If you find that some of your rides are resulting in some time spent in both Zone 1 and Zone 3, this is entirely normal and is often the distributions pro cyclists end up with at the end of a their sessions too.

As long as the majority of the time is accumulated in the Zone 2 range, and attention is paid towards not letting power drift too high for sustained periods of time, your rides should be effective and purposeful.

Undulating Zone 2 Ride (Indoors)

For an indoor Zone 2 session, we have shortened the overall duration so that the workout doesn’t become to mentally taxing (due to some increased monotony indoors).

Also in line with making the session more engaging, the workout features frequent changes in intensity, undulating between the lower end and the upper end of the typical range.

Changes in cadence are also mentioned in case the cyclist wishes to add another element of change to the workout.

How To Train In Zone 2: Steady Endurance Training Explained

What Is Zone 2?