Core launches new heat training zones to help athletes perform in the heat

Core, the manufacturer of the core body temperature sensor, has announced an app update that will introduce the first generalised heat training zones for users as well as an updated Heat Strain Index designed to help athletes perform in high temperatures. 

We recently reported that the Core sensor itself has been widely adopted in the WorldTour, as Core announced a partnership with 10 teams including BORA - Hansgrohe and Canyon/Sram. A race to stay cool is also a component of the WorldTour performance arms race these days. 

Core says the relationship between skin temperature and body temperature is a crucial data point for informing pacing, heat training and cooling. The brand has looked at over three years of skin and core temperature data from 10,000+ athletes to inform the new mobile app updates. 

The updates, for now, take the form of an updated user interface, new Heat Training Zones and guidance, and an updated Heat Strain Index. The Core app and updates are free for all registered users and it sounds like more updates are due in the coming months.

The new Heat Training Zones and Heat Strain Index 

Core's new Heat Training Zones are based on the Heat Strain Index which Core says will allow athletes to 'train hot and race cool'. Core says the Heat Zones are thresholds which are meant to make core body and skin temperature readings easier for regular riders to understand and use. While plenty of riders already complete heat acclimatisation training, the brand says this will enable coaches to assign workouts to be completed in a specific heat zone. Athletes and amateur riders can also 'self-coach' more easily with help from the core website and app. 

The Heat Strain Index is Core's name for mean body temperature. Core's new and improved Strain Index formula converts mean body temperature into a value which ranges from 0 - 10. This can give riders a measure of how hard the body works to stay cool. Core says this improved formula will further help athletes learn about the thermal stress they are experiencing and 'how hard they work to stay cool'. Heat Strain Index can also be displayed live on the Core app and on Garmin smart devices. 

The above image shows how users can reference their Heat Strain Index score and see which Heat Training Zone this equates to and what that might mean for their performance on the bike and how they deal with the heat. 

Why does this matter? High heat strain will potentially result in more effort being needed to produce the same power on the bike, this means riders who aren't cool enough will experience a drop in performance. We have a feature in the works exploring this and just how much emphasis top-level teams are placing on cooling now. Simply put, the riders that stay the coolest will be able to produce more power when it matters.