Physiological changes occur as we train and race in the heat and some considerations should be made. Many Durata athletes’ have been bringing this up with their coaches here in the first real week of hot Texas weather and if you’re not in TX don’t worry it’ll be hot where you are or are racing soon enough, so read up
Fatigue has been shown to develop in an athlete once a core temperature of ~40deg Celsius is reached. Interestingly it does not matter how well trained the athlete is, what there acclimatization is like, body size, starting temperature or relative intensity. The only thing that these variables may influence is the amount of time it takes to reach the 40deg mark. For example someone that is acclimatized to TX summers or has better fitness may be able to go longer at a relative workload before reaching 40deg core temperature than someone that is not acclimatized. Unfortunately the larger the athlete the more heat seems to negatively affect their performance. The good and bad news is that heat affects everyone, so if you have properly prepared for it and can tolerate it more effectively then you will triumph over your competition.