Garmin Stamina Curve and Stamina Zones Explained

 

Garmin’s Real-Time Stamina feature is gaining two useful tools that make stamina data easier to apply to training: Stamina Curve and Stamina Zones.

Rather than simply showing how much stamina you have left during an activity, these tools help you understand how your current fitness translates into sustainable pace or power — and how different effort levels are likely to affect your stamina.

What Is Garmin Stamina Curve?

Stamina Curve shows how long you are expected to maintain different levels of effort before your stamina runs down.

It gives you a picture of your endurance across a range of intensities, from easy efforts through to near-maximal efforts.

For runners, the curve is based on pace. For cyclists, it is based on power. This makes it useful for answering practical questions such as:

• How fast can I realistically run for a particular duration?
• How much power can I sustain on the bike?
• Is my planned race pace realistic?
• Is a workout intensity sustainable?
• Has my ability to maintain longer efforts improved?

The curve can also show where your fitness is developing. For example, your training may improve your ability to sustain high-intensity efforts, your long-duration endurance, or both.

What Does Stamina Curve Measure?

Stamina Curve uses Garmin’s real-time stamina modelling to simulate how your stamina is expected to respond at different effort levels.

The model takes several factors into account, including:

• Energy expenditure
• Estimated training load
• Effort accumulated above your lactate threshold
• VO2 max
• Lactate threshold for running
• FTP for cycling
• Your ability to tolerate anaerobic efforts
• Your ability to maintain long-duration efforts
• Your recent and longer-term training history

The system then estimates how long you could maintain a particular pace or power level before reaching a physiological limit.

In simple terms, the harder you go, the faster stamina is expected to fall.

How to Use Stamina Curve

Stamina Curve is particularly useful for planning and analysing training and races.

You can use it to:

• Plan a realistic race pace
• Check whether a planned workout intensity is sustainable
• Understand the relationship between pace, power and duration
• Track how your endurance profile changes with training

For example, if your planned race pace sits at a level where the curve predicts a relatively short sustainable duration, that may indicate that the pace is difficult to maintain for the entire event.

The curve therefore gives you another way to look at pacing beyond simply asking how fast you can run or how much power you can produce.

Important Limitations of Stamina Curve

The predictions are based on your current fitness and assume that you are well recovered.

They also assume relatively steady pacing.

Real-world activities are rarely perfectly steady. Hills, accelerations, attacks, changes in pace, and other variations in effort can cause stamina to drain differently than predicted.

Garmin also states that the estimates are most accurate for intensities up to VO2 max.

The curve should therefore be treated as a performance guide rather than a guarantee of exactly how long you will be able to maintain a particular pace or power.

What Are Garmin Stamina Zones?

Stamina Zones take the information behind the Stamina Curve and turn it into five personalised effort ranges.

The zones are designed to make stamina easier to use during an activity, particularly when you are trying to control your effort.

There are always five zones, ranging from easier efforts through to maximal intensity.

The actual pace or power associated with each zone changes as your fitness changes.

How Garmin Stamina Zones Work

The zones are personalised using your physiological data.

For running, they use information such as:

• Lactate threshold pace
• VO2 max estimates
• Your training history

For cycling, the system uses:

• FTP
• VO2 max estimates
• Your training history

The result is a set of effort ranges that are linked to how Garmin expects your stamina to respond.

This connects the intensity you are producing with the rate at which your stamina is likely to decline.

How to Use Stamina Zones

Stamina Zones are primarily designed to help you control effort in real time.

During a workout, they can help you stay within your intended intensity range. This can be particularly useful when a workout calls for a controlled effort rather than simply running or riding as hard as possible.

After the activity, you can also review how much time you spent in each zone.

This can help you understand:

• Whether you followed your intended pacing
• How your effort was distributed
• Where you may have spent too much time at higher intensity
• How your pacing affected stamina during the activity

Stamina Curve vs Stamina Zones

Although both features are part of Garmin’s stamina system, they have different purposes.

Stamina Curve is primarily about planning and understanding your capabilities. It shows how sustainable different effort levels are across different durations.

Stamina Zones are primarily about controlling effort during training. They divide your intensity into five personalised ranges you can use to stay on target.

Put simply:

• Stamina Curve: How long can I sustain this pace or power?
• Stamina Zones: How hard should I be working right now?

The two features complement Garmin’s existing Real-Time Stamina data by making it easier to turn the stamina information into practical training decisions.

How Stamina Curve and Zones Fit Into Real-Time Stamina

Real-Time Stamina already provides two important measurements: Stamina and Potential Stamina.

Stamina represents how much performance capacity you have left at your current effort level. Hard efforts, such as sprints, climbs and attacks, can cause it to fall quickly.

Potential Stamina represents the effects of deeper, longer-lasting fatigue. This can include muscle damage, nervous-system fatigue and depleted glycogen stores.

During a sustained moderate effort, Stamina and Potential Stamina may remain relatively close.

Increase the intensity beyond your lactate threshold when running or FTP when cycling, and Stamina can fall faster than Potential Stamina. Once you return to a more sustainable effort, Stamina can gradually recover towards your Potential Stamina.

Stamina Curve and Stamina Zones add another layer to this information:

• Real-Time Stamina shows how much capacity you have left.
• Stamina Curve shows how sustainable different effort levels are.
• Stamina Zones show where your current effort sits within five personalised intensity ranges.

Why These New Stamina Tools Matter

The main change is that Garmin’s stamina information becomes more useful for planning as well as monitoring.

Instead of only looking at stamina during a run or ride, you can use the Stamina Curve to explore how your current fitness translates into different durations and intensities.

Stamina Zones then provide a simpler way to apply that information while you are actually training.

Together, they can help you:

• Plan race pacing
• Set realistic workout intensities
• Manage effort during long sessions
• Understand how your endurance is changing
• Review whether you executed a planned pacing strategy

Summary

Garmin’s Stamina Curve and Stamina Zones build on the existing Real-Time Stamina feature.

The Stamina Curve gives you a broader view of your performance by showing how long different levels of running pace or cycling power are expected to remain sustainable.

Stamina Zones take that information and divide your effort into five personalised intensity ranges, making it easier to control your effort during a workout.

The key difference is simple:

• Stamina Curve helps you understand what you can sustain. Stamina Zones help you control how hard you are working.
• Together with Real-Time Stamina and Potential Stamina, they give Garmin users a more detailed way to understand how current fitness, training history and exercise intensity affect endurance performance.

Further reading

• Garmin Fenix 9 vs Fenix 8: which to buy
• Fenix 9: new features explained
• Fenix 9 features will pass to existing Garmin watches
• Garmin Fenix 9 Pro specifications

Last Updated on 3 October 2026 by tfk the5krunner