There’s no denying cycling is becoming more and more high tech with advances in materials, nutrition and human performance allowing athletes to push the boundaries of what was thought possible. Much of the advances can be attributed to data and the potential to gather data. Tire rolling resistance can be measure more accurately, aerodynamic drag can be measured on the fly and now, thanks to CORE, it’s possible to measure core body temperature externally. 

3.5/5

£230 | Buy from CORE

Highs: 

• Could be a powerful training tool in the right hands

• Seamless connection to devices

• Good battery life

Lows:

• Data requires a deeper level of understanding than power or heart rate

• Battery life is poor

The Lowdown:

• Continuous, accurate core body temperature monitoring

• Accuracy backed by clinical, lab, and field tests

• Automatically sends data to wearables + training apps

• ANT+ and Bluetooth compatible for easy pairing

Heart rate and power meters have been a mainstay in the professional peloton for many years now allowing athletes to fully understand what their body is doing and how to ensure it can be in peak performance but now there’s the ability to monitor body temperature to ensure athletes know their limits and can take preventative measures to ensure they don't overheat causing a huge drop in performance. 

CORE claims to be the ‘first and only core body temperature sensor that delivers continuous and accurate monitoring without probes or e-pills’. It works by measuring the thermal energy transfer to or from the body which when paired with an algorithm can calculate your core body temperature. 

CORE measures and records a number of metrics; Core body temperature, skin temperature, heat strain and heat zones with all the data visible in the app or on selected head units but might not have the correct units. Garmin has an app on the IQ platform that integrates with CORE but Wahoo users will have to use a different data field with different units. This data can then be analyzed in your training tool of choice. 

Why does body temperature matter?

Much like training at altitude which tricks the body into adapting to an environment with less oxygen, heat stress stimulates your body to produce more blood plasma which enables higher performance and measuring core temperature allows you to safely put your body under heat strain. The sensor is predominantly aimed at pro teams with riders from Inoes, Lidl-Trek and Soudal Quick Step all spotted with the sensors. 

CORE say there are three main use cases for the sensor, heat training, active cooling and avoiding overheating. Depending on your goals, one or more of these facts may appeal to you but it’s interesting to see multiple applications for the tech.

CORE Body Temperature Sensor in use

The CORE sensor attaches to either a heart rate strap or with one of the included stickers and is almost unnoticeable. From testing, it also doesn’t seem to require a lot of pressure on the skin to measure temperature. Unlike a heart rate monitor that requires reasonable pressure not he skin, CORE just needs to be in contact with the skin.

Also in the box is a magnetic USB charger which will give the CORE sensor roughly 6 days of run time. There’s a green LED on the sensor that indicates when it’s charging but not when it’s fully charged annoyingly, this has to be checked in the app. I found the magnetic charge connector to be a little temperamental, requiring careful positioning and care to ensure it wouldn’t then be knocked off. The sensor switches on when it detects motion but I found it to switch itself on even when moving it across my desk and noticed that the battery drained quite quickly. It’d be useful if the app could send a notifcation when the battery was running low to allow for preemptive charging rather than heading out for a ride and discovering the battery is flat.

To get the most out of the sensor, CORE suggests doing a heat ramp test to establish your ‘heat zones’. There is guidance on the app and website for how to do the test but it essentially involves riding until your core temperature reaches 38c and then maintaining a steady heart rate until your power output drops by 20%. It’s not as unpleasant as it sounds and was pretty straightforward to complete. This data can then be used to develop training strategies in the future. 

All of the data feeds back into the app which presents it in graphs and tables for easier digestion. I found the app to be slick and responsive but could offer more analysis of the data. 

The device costs £230 so it’s certainly aimed at serious riders looking to get the most from their training and some of the data is interesting but for me personally, I didn’t find it added a huge amount to my riding. If you have specific training objectives however or find yourself struggling in higher temperatures then it may be a worthwhile training tool, or if you’re seeking every last marginal gain. In my eyes it’s a really interesting piece of tech that in the right hands could be very powerful but still needs a little more work to really appeal to a wider audience.