When your core temp rises during intense exercise, your power and pace decline.
That's why the world’s best coaches and athletes use CORE to facilitate heat training for optimizing performance
Train Hot
CORE allows you to safely facilitate heat training, which has been proven to increase hemoglobin mass, VO2max, lactate threshold, power output, and blood plasma during controlled laboratory studies.
Race Cool
Heat adaptations allow you to stay cooler for longer, increasing your performance on race day regardless of the temperatures. CORE also allows you to monitor your thermal vitals in real-time so you can pace and cool accordingly.
Trusted by Top Athletes and Coaches
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GUSTAV IDEN 2022 IRONMAN WORLD CHAMPION
“I’d never raced in Kona before. People thought I couldn’t win without experience in the island’s legendary heat and humidity, but I was extremely well prepared because I had used the CORE sensor to simulate the core body temperatures I would experience during the race. I adapted to those elevated core temps as if I’d always trained and raced in Kona.”
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COACH CARLES TUR WORLDPRO CYCLING COACH
“CORE enables us to measure the core and skin temperature of our riders which is very useful for understanding the body’s thermal response to effort, particularly in hot and cold environments and how that affects performance. This allows us to understand the individual response of each rider, enabling us to implement heat protocols to enhance performance.”
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TOM EVANS 2023 WESTERN STATES ENDURANCE RUN WINNER
“I used CORE in the build up to the Western States 100 because heat training is essential for success in that race. CORE took the guessing out and I trained more specifically than ever, allowing me to improve my heat acclimation and also plan a specific cooling strategy. It was a game changer.”
Train Hot, Race Cool
Frequently Asked Questions
Your muscles generate heat when they’re working hard. Generate enough heat, and your core body temperature will rise. Your body will try to cool itself by diverting blood from the muscles to the skin where it’s cooled by sweat evaporation, which leads to decreased speed and performance. But you can minimize this effect in two ways. First, by monitoring your core temperature, you can make strategic cooling and pacing decisions during training and racing, helping you stay cool and maximize your performance. Second, you can use heat training to help you adapt to higher internal body temperatures come race day. This can lead to radically better performance - in one study, cyclists improved their speed by 8% in a time trial, after heat training for just 10 days prior to the race.*
The CORE sensor measures both core body temperature and skin temperature. Those metrics are displayed live in the CORE app and on compatible sports tech devices. The app and some Garmin devices also display the real-time Heat Strain Index, which shows the amount of heat stress the body is experiencing.
When you’re heat training, use CORE data to keep your core temperature within your heat training zone. During racing, CORE data can tell you when to use cooling strategies and when to reduce power/pace so that you don’t overheat.
Maximum benefits are gained by doing 10–12 sessions within 2–6 weeks. Most athletes will experience the majority of gains after 4–5 sessions and benefits can be maintained through the season with just 2–3 sessions per week. Each session should involve a continuous effort of 45–60 minutes within the heat training zone. This is the recommended course of training, though even less frequent heat training has been shown to be effective at improving performance come race day.
Heat training adapts the body to perform more efficiently at elevated core temperatures. It also builds blood plasma and hemoglobin, which increases performance (increased power at both lactate threshold and VO2max) in both cool and hot conditions alike.
The impact of heat on human performance has been thoroughly studied and understood. It’s well documented by sports scientists that heat training increases the body’s ability to cope with higher heat, to cool itself more efficiently, and to perform in both cool and hot conditions. Physiological changes include increased blood plasma and hemoglobin, increased sweat rate, and earlier onset of sweating. Learn more from this selection of relevant research papers.
The CORE sensor measures thermal energy transfer between the body and the environment. An AI-powered algorithm uses this data to calculate core body temperature with medical-grade accuracy. Extensive testing has validated the accuracy of CORE data against internal body temperature data collected with more invasive methods, like ingested electronic pills. This means that athletes can reliably use CORE data to understand what is happening inside their body, with a completely non-invasive wearable that’s the first of its kind. More information on Core’s accuracy can be found in the article Scientific Data Validating CORE’s Accuracy.
The CORE app is available on both iOS and Android platforms. The sensor is compatible with most watches and cycling computers from Garmin, as well as a selection of devices from COROS, Suunto, Wahoo, and Hammerhead. Functionality with Apple and wearOS watches is still limited, but improved. Training software with full compatibility include Today’s Plan, Intervals.icu, and Golden Cheetah. The premium version of Training Peaks is also compatible. Please see the CORE Sensor Compatibility page for full details - we are continuously updating our list of compatible platforms and devices.
To get the most precise data during sports activity, we highly recommend pairing with a heart rate monitor. Heart rate helps the sensor accurately convert measured heat flux into core body temperature. During everyday activity (ie. non-sports), core temperature data is accurate both with and without a heart rate monitor.