Heat training throughout the season will give you the best performance gains. In addition to increasing your blood plasma and haemoglobin, it prepares you for races in hot environmental conditions. But what if you haven’t been heat training and want to prepare for an upcoming hot race? Here’s how you can do it in two to four weeks.

The number of days required for heat adaption varies amongst individuals, but fourteen days works well for most athletes. Depending on travel plans and how heat training meshes with other workouts, you'll want to begin your heat training two to four weeks before your event. If you complete the heat training block more than a couple of days before competition, you'll want to do maintenance heat training until the start of the event.

Acclimatisation or acclimation?

Acclimatisation means training in the same conditions you’ll experience on race day. Important factors are the air temperature, relative humidity, and sun exposure. Acclimation involves simulating race-day conditions by artificially heating an indoor room or wearing extra clothes while training outdoors. If training indoors, use boiling water or humidifiers to increase the humidity to expected race conditions.

Three easy steps

Step 1. Heat ramp test

Before beginning heat training, you’ll need to do a heat ramp test to find your heat training zone.

Step 2. Heat block training

The next step is to complete two weeks of heat block training. This involves keeping your core temperature in your heat training zone for 45–90 minutes each day. For more details, see the guide for heat training.

Remember that passive heating can complement active heat training. This involves extending the heat portion of a workout by using a hot bath (40°C/104°F) or sauna (70–90°C/158–194°F). Passive heating can make your heat training more compatible with the rest of your training. (Please note that the CORE sensor is not yet recommended for use in the sauna.)

Step 3. Heat training maintenance

If your two-week long heat block training ends more than a couple of days before your competition, you will need to maintain your heat training. This requires elevating your core body temperature into the heat training zone for 45–90 minutes per day, 2–3 days per week. This can be done with the strategies discussed in the heat block training section.

Additional Resources

Additional information on heat adaption can be found here: CORE's Heat Training for Sporting Performance, and Beat the Heat: Tokyo Olympic Games 2020.