CORE BODY TEMP SENSOR

£205 ▶ A worthwhile purchase for data fiends?

These days you can measure your stride length, stroke length, glycogen levels, sleep pattern and so on. And, 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 noninvasive 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? Well, the key reason’s 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.