How to Identify Temperature Zones

The CORE mobile app contains six zones set up with sample temperatures boundaries 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! You can change these zone thresholds in the settings box (tap the icon in the upper right corner of the app).

Find your heat training zone

The first step is identify your heat training zone by conducting a heat ramp test on either a bike trainer or the treadmill. This will tell you the core temperature range that causes physiological adaptions without causing undue exhaustion. This lets you identify zones 5, 4 and 3.

5. 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.
6. Heat training zone. As identified in your heat ramp test. When in this zone for 45–75 minutes, your body adapts to improve your efficiency and performance without causing excessive fatigue.
7. 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. This zone simulates a mild fever and causes a short-term immunological benefit.

Find your low activity zone

The next step is to find your low activity zone by wearing your CORE sensor 24 hours/day for several days. Use the mobile app to note the range of core temperatures when you are not exercising or doing hard physical labour.

2. Moderate activity zone. This is the temperature range between zones 1 and 3. It coincides with activity that is less intense than athletic training – perhaps walking outdoors, or performing household chores. Find this zone by first identifying the zone 1 boundaries (below).
3. Low activity zone. The lower boundary of this zone is your lowest core temp while sleeping, typically found about an hour before waking. The upper boundary is when you are awake but sitting or otherwise relaxing, and typically occurs in the late afternoon or early evening. Note that women’s lowest core temperature will vary based on the phase of their menstrual cycle. That minimum will vary 0.3 °C–0.6  C (0.5 °F–1.0 °F) throughout the cycle. More details are found in this article.
4. Cool zone. This is everything below the low activity zone.

Becoming heat aware.

Identifying these temperature zones will help you become heat aware. The Train with CORE articles, Basic Heat Awareness and Advanced Heat Awareness show some ways of doing that.