CORE 1

Frequently Asked Questions

Here are the answers

Why is core body temperature important for performance?

Muscles generate heat when working during activity. If we generate enough heat, core body temperature rises. The body tries to cool down by redirecting blood from muscles to skin, where it cools by sweat evaporation, leading to reduced speed and performance. However, we can minimize this effect in two ways. First, by monitoring core body temperature we can make strategic decisions about cooling and pace during training and races, which helps stay cool and maximize performance. Second, we can use heat training to adapt to higher internal body temperatures on race day. This can lead to radically better performance – in one study, cyclists improved their speed by 8% in time trials after just 10 days of heat training before races.

What data does CORE measure and display?

The CORE sensor measures core body temperature and skin temperature. These metrics are displayed live in the CORE app and on compatible sports devices (typically GPS watches or bike computers). The app and some Garmin devices also display real-time heat strain index, which shows the amount of heat stress the body is facing.

How to use CORE during training or racing?

During heat training, you can use CORE data to maintain core temperature within your heat training zone. During races, CORE data can tell you when to use cooling strategies and when to reduce power or pace so your body doesn't overheat.

How much heat training do I need to achieve results?

Maximum benefits are achieved by completing 10 – 12 training sessions over 2 – 6 weeks. Most athletes notice most improvements after 4 – 5 sessions and benefits can be maintained during the season with just 2 – 3 sessions per week. Each session should include continuous effort for 45 – 60 minutes within the heat training zone. This is the recommended training course, although less frequent heat training has also proven effective in improving race day performance.

I only race in cold weather. Why should I add heat training to my preparation?

Heat training adapts the body for more efficient performance at elevated core temperatures. It also increases blood plasma and hemoglobin volume, which improves performance (increased performance at lactate threshold and VO₂ max) in both cold and hot conditions.

What is the scientific basis for heat training benefits?

The effect of heat on human performance has been thoroughly studied and understood. Sports scientists have well documented that heat training increases the body's ability to handle higher temperatures, cool more efficiently, and perform in both cold and hot conditions. Physiological changes include increased blood plasma and hemoglobin volume, increased sweating rate, and earlier onset of sweating. A list of scientific studies supporting these findings can be found here.

Is the CORE sensor really accurate? How is it tested?

The CORE sensor measures heat energy transfer between the body and environment. An algorithm using artificial intelligence uses this data to calculate core body temperature with medical accuracy. Extensive testing has confirmed the accuracy of CORE data compared to internal body temperature data obtained by more invasive methods, such as electronic ingestible pills. This means athletes can reliably use CORE data to understand what's happening in their body using a completely non-invasive wearable device that is the first of its kind. More information about CORE accuracy can be found here.

Is the CORE sensor compatible with my watch, bike computer or app?

The CORE app is available on both iOS and Android platforms. The sensor is compatible with COROS watches (native compatibility, watches must contain software from January 2022 and later), as well as most watches and bike computers from Garmin, Suunto, Wahoo and Hammerhead. Functionality with Apple watches and wearOS is still limited but improving. Training software with full compatibility includes Today's Plan, Intervals.icu and Golden Cheetah. Premium version of Training Peaks is also compatible. A detailed and updated list of all compatible devices can be found here.

Do I need a heart rate monitor (chest strap) to use the CORE sensor?

To get the most accurate data during sports activity, pairing CORE with a heart rate monitor (chest strap) is strongly recommended. Heart rate helps the sensor accurately convert measured heat flux to core body temperature. During regular daily activities (e.g. outside of sports), core temperature data is accurate with or without a monitor. Consider using the CORE sensor with COROS Heart Rate Monitor.