Train with CORE: Temperature Zones

Once you’ve established a basic heat awareness by wearing your CORE sensor during workouts, it’s time to identify your temperature zones. Just like power zones and heart rate zones, temperature zones guide you in your training and racing.

In the CORE mobile app, you’ll notice six zones set up with sample temperatures (based on population-wide averages). However, each athlete is different, and these numbers may or may not be suitable for you. It is important to establish your own personal temperature zones!

Identifying your temperature zones

The first step is to conduct a heat ramp test on either a bike trainer or the treadmill. This hour-long test will identify your optimal heat training zone. Keep in mind, this may not be as hot as you are expecting – rather, it is the core temperature at which your body can start to physiologically adapt. Training too hot will exhaust you and training too cool will be ineffective.

From the temperatures of your heat training zone you can identify your other temperature zones. Enter these into the CORE mobile app (tap the settings icon in the upper right of any screen).

  1. Red Zone. Everything higher than your heat training zone. Try to avoid this zone during training – it can cause excess fatigue, does not provide additional benefit, and can even be dangerous.
  2. Heat training zone. As identified in your heat ramp test. Within this zone your body adapts to improve your efficiency and performance.
  3. Workout zone. This zone spans approximately 0.3° C/0.5° F below your heat training zone. So, if the lowest temperature of your heat training zone is 38.3° C, your workout zone would be 38.0–38.3° C. In Fahrenheit, if the lowest temp of your heat training zone is 100.9° F, your workout zone would be 100.4–100.9°F.
  4. Moderate activity zone. After you’ve set zone 1 and zone 3 temperatures, the range of this zone will be set automatically. While zones 2 and 3 do not contribute to heat training, raising your body temperature above baseline provides health benefits.
  5. Low activity zone. This is your everyday living zone, and core temperature fluctuates within this zone throughout the day and night. To identify this zone, wear your CORE sensor at the start of a week for several consecutive days (including during sleep). Using the plots on the mobile app, see what your typical range of core temps are when you’re inactive. At rest, core temp is generally lowest soon before waking up, and highest in the late afternoon or early evening.
  6. Cool zone. This is everything below the low activity zone.

Next steps

Once you’ve identified your temperature zones, you’re ready to advance your heat awareness even further. The next step is to perform specific workouts in several of those zones.