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Home / Reviews / Core Body Temperature Sensor review - Tri-tech - Gear

Core Body Temperature Sensor review

Is this temperature sensor useful for athletes, or is it just another gimmick? James Witts finds out...

Core Body Temperature Device

These days you can measure your stride length, stroke length, glycogen levels, sleep pattern and so on.

Now, thanks to this device, that includes core body temp, which is used by many triathletes, including Kristian Blummenfelt.

We’ve exercised with e-pills before, but this is the first non-invasive consumer device to measure core temperature.

It works via what’s called a thermal-energy transfer sensor, which bases its readings on the Seebeck effect.

Essentially, when heat passes through a sensor, it generates a voltage signal proportional to the energy passing through. Tracking this means that the overall thermal energy transfer can be measured in real-time.

The sensor can either be clipped into a heart rate monitor strap or stuck to your chest via one of Core’s supplied stickers. Though, the former felt more comfortable and assured.

But why should I measure core temperature? Well, the key reason is if you’re racing in hotter climes and are looking to acclimatise.

With this device, you can safely and meticulously increase the intensity of your sessions in the heat based on how your core temperature is coping with the thermal stress.

With this info, you can more precisely design hydration and cooling strategies. In theory, and perhaps with third-party input, you can also more accurately pace your race, warm up and analyse gear choices.

The app’s highly usable and, rather usefully, you can now see the data on certain Garmin, Wahoo and Coros watches. Sure, it’s not as accurate as pills or rectal probes, but it’s sound enough.

Verdict: More data and another cost but benefits are more than skin deep.

Score: 80%

Profile image of James Witts James Witts Freelance sports writer and author


Former 220 Triathlon magazine editor James is a cycling and sports writer and editor who's been riding bikes impressively slowly since his first iridescent-blue Peugeot road bike back in the 80s. He's a regular contributor to a number of cycling and endurance-sports publications, plus he's authored four books: The Science of the Tour de France: Training secrets of the world’s best cyclists, Bike Book: Complete Bicycle Maintenance, Training Secrets of the World's Greatest Footballers: How Science is Transforming the Modern Game, and Riding With The Rocketmen: One Man's Journey on the Shoulders of Cycling Giants