Pauliena Rooijakkers of Canyon//SRAM Racing created a textbook case study on how to ‘Train hot, race cool’ in preparing for and racing the Itzulia Women 3-day stage race. Pauliena says, ‘I always try to dress warmly in training to better withstand the heat in the races. I notice that my body can tolerate heat better because I dress myself warmly the days before.”
Pauliena kindly shared her CORE data leading up to the race, and it reflects her strategy. During the week of May 1, she trained on 5 days where her Heat Strain Score was between 782 and 1624. These are all quite high scores and are a result of several hours with elevated core and skin temperatures. She generated a lot of heat by riding hard, and she trapped that heat by wearing extra clothes.
This chart is typical of those training days. Her core temp was not extremely high – mostly in the heat training zone and only climbing above 39.0° C/102.2°F at the end. But because of the extra clothes and elevated skin temperature, her Heat Strain Index was quite high – over 4 for about 2 hours, and reaching 5 and 6 for shorter peaks.
The 5 days of riding like this prepared her for the heat generated by the intensity of racing. Her body produced more plasma and became more efficient at sending blood to the skin for cooling – all of which result in better cooling and less loss of power.
During the race, we can see how her core temp and Heat Strain Index remained relatively low, even with the increased intensity of racing. Even on Sunday – a very strenuous day with an almost continuously elevated heart rate, her core temp only once rose above 39° C/102.2° F, and her Heat Strain Index generally stayed below 3.
On these two race days, her Heat Strain Score was 208 and 577 – well below what she had trained at the week before.
Because she had trained in days with more thermal load than she experienced on race day, Pauliena found these days quite comfortable from a temperature perspective. She had acclimated well, and heat was not an issue for her.
Compare your own data
We often repeat the phrase, ‘Train hot, race cool’ – and Pauliena’s case is a perfect example of why. As you train and race, look for patterns in your data. If you record a number of training days with a higher Heat Strain Score and Heat Strain Index than you do when racing – you’re probably preparing yourself well. But remember that core temps during training should not be extreme – simply elevated into your heat training zone.