Core Body Temperature Sensor Review

My Review of the Core Body Temp Monitor

You get to a point 15 years in, where the gains are getting smaller (or reversing) so I’m always looking for ways to improve my performance (preferably ones I can buy 😉) So when I see this little white tile adorned to the HR strap of the world's best triathletes, I'm interested. 

Enter the Core Body Temp Monitor. 

The theory makes sense. 

Here comes the science bit:

The human body regulates core temperature by balancing heat production and loss, primarily through sweating and increased skin blood flow.

During intense exercise or high heat and humidity, the body’s cooling mechanisms may struggle to keep up, leading to heat strain, which increases core and skin temperature and raises heart rate, reducing performance. 

Mean body temperature, combining core and skin temperature, is a key indicator of heat strain, and the CORE sensor supposedly estimates this using a specialized formula. The sensor records and the app shows you how hard the body is working to stay cool, with higher values indicating greater strain. Keeping the Heat Strain Index low through cooling or pacing helps maintain performance

Naturally, I was keen to give it a try—but my experience with it has been frustrating from the start.

Initial Setup and First Impressions

On paper, the Core Body Temp Monitor is exactly what you’d want in a high-performance training tool. It’s small, lightweight, and easy to attach to a heart rate strap. There isn't even an buttons!! 

So far, so straightforward. The idea is that it syncs with the app, providing real-time temperature data you can use to adjust your intensity and cooling strategies mid-session. 

But from the beginning, it was more trouble than it was worth.

Connectivity Issues

The app consistently struggled to pick up the device. Sometimes it would pair, sometimes it wouldn’t. On the occasions it did connect, it would frequently drop out mid-session, leaving me guessing about my actual core temperature. 

Glitches and Inaccuracy

Even when it did stay connected, by fudging it on the app (whilst trying to carry out your session) I could keep it connected but the data lag was hugely frustrating. Restarting the app and the device became a regular part of my training routine—hardly ideal when you’re in the middle of a turbo.

Poor Support and No Refunds

I'm a patient man, but eventually my patience snapped when the device stopped working entirely. I reached out to Core’s customer support, only to be met a wall of obstacles as to why a refund couldn't be offered. 

They wouldn’t offer a refund because I was outside their strict 30-day return window—despite the fact that the device had clearly failed. For a product at this price point, you’d expect better customer service and more confidence in their product’s longevity. 

So if you are considering getting one, remember that they won't honour EU Consumer rights and refund for a faulty product.

What I Learned About Heat Adaptation

Ok, enough whinging, in the limited time I was able to use the Core Body Temp Monitor, I did manage to correlate some useful insights about heat adaptation. It confirmed that training at elevated temperatures does improve your ability to perform in the heat. 

Riding indoors without a fan or with reduced cooling essentially mirrors the heat stress needed to build that adaptation. So, while the monitor gave me some confirmation of the process, it’s nothing groundbreaking—most experienced athletes or regular Zwifters are probably already heat-adapting without realising it.

New Tech, Old Problems

Part of the problem seems to be that this is still relatively new technology from a small scale supplier. Bugs and glitches are to be expected with new tech, but the defensiveness in their responses to customer issues makes me question whether these problems will ever be fully resolved. Instead of taking user feedback on board to improve the product, they seem more interested in fighting the issue with you.

Verdict

The concept behind the Core Body Temp Monitor is promising—but the execution falls flat. Between unreliable connectivity, inconsistent data, poor customer service, and the refusal to stand behind their product, it’s hard to justify the investment.  If you can’t trust the data or the company to support you when things go wrong, then it’s not a tool worth relying on. Until Core figures out these issues (if they ever do), 

I’d recommend steering clear, instead come to Comeragh Coaching, where I'll have you heat adapted in no time, with none of the hassle.