Understanding Garmin Heat & Altitude Performance Acclimation

August 28, 2022 Ivan Jovin How to, Smartwatch 6 min read

Garmin Heat & Altitude Performance Acclimation is functionality that aims to eliminate the influence of environmental factors in training performance calculations. Here’s everything you need to know.

Garmin Heat & Altitude Performance Acclimation – what is it?

Demanding conditions and climates can have an impact on how you train. This is because exercising at very high temperatures or high altitudes is more difficult. Your body needs time to adjust. Which in turn can have a temporary effect on the accuracy of your VO2Max and Training Status calculations. For example, while training at high altitudes may have a positive effect on your fitness and endurance, on older Garmin watches you may see a temporary VO2max decline.

Essential reading: Top fitness trackers and health gadgets

A few years ago the company introduced something called Heat & Altitude Performance Acclimation. Basically, this aims to reduce the impact of environment factors when it comes to calculating performance and effort. As your body adjusts, so do your measurements. The functionality kicks in if you are training in outside temperatures that are above 22ºC (72ºF) or when the altitude is above 800 meters (2625 feet).

This is particularly important for those who travel to different locations, around the year. Or you simply may have gone to a warm destination for vacation. Needless to say, your body will perform better when it is fully adjusted. The more you are used to the heat and/or altitude, the less of an impact it has. This is the acclimation process.

Garmin Heat & Altitude acclimation:

allows you to track environmentally triggered adaptation
it enhances the reliability of performance metrics

Changes in heat can cause a complex series of adaptations in the body in response to stress. You will need time to adapt as it will be more difficult to maintain a normal body temperature. Until you are fully acclimatised.

Training at higher altitudes means less oxygen in the air. So with more limited access to this vital resource, your body will need to work harder to adapt.

Adjusting to heat changes

Heat performance adjustments need weather data from a connected phone in order to work. So make sure that you have set location access in your smartphone settings for the Garmin Connect app to “Always”. Otherwise the functionality will not work each and every time.

So while your Garmin watch or bike computer may have a temperature sensor inside, that info is not used to calculate the outside weather conditions. For best results, make sure your watch has a Bluetooth connection to your smartphone before you head out for a run or ride.

The metric quantifies on a scale between zero and 100% how well you are adjusted to training in the heat. You can follow a chart showing a historical overview of the readings. For someone who permanently lives with temperatures above 22ºC (72ºF), the info will let you know if you are trending up or down.

Keeping an eye on those types of readings can help you pace your effort. Any significant increase in heat and your body will, at first, respond by increasing the heart rate and body temperature during exercise. Probably not a good idea to attempt a PB in those conditions!

It is worth noting that it takes at least 4 training days for full heat acclimation to take effect. And the functionality only works for GPS-tracked activities. Non-training days have no effect so you do not need to heat out 4 days in a row. However, if you have not trained for more than 3 days in the heat, the acclimation calculations will begin to lose accuracy. After about a month away from the heat, most people’s tolerance will have returned to their baseline.

The final word of note – acclimation is faster in hotter temperatures. You can also expedite it with high-intensity workouts such as HIIT.

Adjusting to changes in altitude

As with heat adjustments, you will need to allow “Always-on” location access in your smartphone settings for altitude acclimation to work. That’s because the watch or cycling computer checks the living altitude level by tapping into your smartphone readings once per day. It does this to make sure the information gathered from its sensors are accurate.

What you’ll get is a metric that displays the elevation that your body is currently acclimated to. You’ll see the acclimation progress with a nifty altitude scale.

The values and how quickly you adapt depend on a number of factors. For example, if you train at higher altitudes, it will allow you to adapt more quickly to a lower altitude. So let’s say you train at, for example, 4000 meters altitude. You will adjust more quickly to, let’s say, an altutude of 2000 meters than you would if you trained at 2000 meters. Professional athletes use this tactic to prepare for important events.

As mentioned, the minimum Gаrmin acclimation value is 800 meters. The maximum is 4000 meters. If you are outside these parameters, you’ll see a message that Altitude Acclimation is inactive. Or you simply might not see anything. The same applies to Heat Acclimation.

It takes about three weeks for total adaption to living altitude. If you do not train for that amount of time at high altitudes, decay in altitude adaptation will begin.

How do I check my Heat or Altitude Performance Acclimation?

The functionality works in the background but you can keep track of the metrics in the Training Status widget. There are a number of ways to access the readings.

The easiest way is through the Garmin Connect app. Heat and altitude acclimation can be found in Perfomance Stats > Training Status. The equivalent is also located in the web dashboard under Reports > Training Status. Finally, you can also access the readings in the Training Status widget on your watch or bike computer.

Which Garmin watches have Heat & Altitude Performance Acclimation?

As mentioned, Heat & Altitude Performance Acclimation has been available on a select group of Garmin watches and bike computers for a while now. It can currently be found on of the following devices.